✅ DDx: Abdominal Pain / Diarrhea / GI Bleed Flashcards

Question

Hiatal Hernia

Answer 1

Hiatal hernias occur when intraabdominal organs protrude into the thoracic cavity. Most (\>90%) hiatal hernias are sliding hernias, which occur when the gastroesophageal junction and proximal stomach slide into the chest. Sliding hernias are usually asymptomatic or result in reflux symptoms (eg, heartburn). In contrast, PEHs occur when the gastric fundus migrates into the thoracic cavity; larger defects can result in the subsequent herniation of the surrounding stomach and intraabdominal organs (eg, bowel, spleen). This results in compression of the stomach and surrounding organs (eg, esophagus, lungs), leading to more severe symptoms. Common manifestations include nausea and vomiting, postprandial fullness, dysphagia, and epigastric and/or chest pain. As the stomach advances into the thoracic cavity, there is risk of respiratory compromise and gastric volvulus. The presence of a **retrocardiac air-fluid level** (due to the stomach bubble within the thoracic cavity) suggests a PEH, although it may also be seen in sliding hernias. The diagnosis is confirmed with barium swallow or upper endoscopy. Whereas symptomatic sliding hernias are generally managed with medical treatment of reflux symptoms, PEHs often require surgical repair.

Answer 2

Presents as difficulty initiating **swallowing** associated with coughing, choking, aspiration, or nasal regurgitation. Typically, patients are evaluated initially with **videofluoroscopic modified barium swallow** to evaluate swallowing mechanics, degree of dysfunction, and severity of aspiration.

Answer 3

Drug Antibiotics * Tetracyclines Anti-inflammatory agents * Aspirin & many nonsteroidal anti-inflammatory drugs Bisphosphonates * Alendronate, risedronate Others * Potassium chloride, iron Pill esophagitis is due to a direct effect of certain medications on esophageal mucosa. Mucosal injury in pill esophagitis can be due to acid effect (eg, tetracyclines), osmotic tissue injury (eg, potassium chloride), or disruption of normal gastroesophageal protection (eg, nonsteroidal anti-inflammatory drugs). Patients usually do not have prior esophageal disease, although pill esophagitis can be worse in those with concurrent gastroesophageal reflux. Typical symptoms of pill esophagitis include **sudden-onset odynophagia** and retrosternal pain that can sometimes cause difficulty swallowing. It is most common in the **mid-esophagus due to compression by the aortic arch** or an enlarged left atrium. The diagnosis is usually made clinically but can be confirmed on endoscopy, which shows **discrete ulcers with relatively normal-appearing surrounding mucosa.** **Tx:** Treatment includes primarily stopping the offending medication to prevent future injury.

Answer 4

Pathogenesis * Chronic, immune-mediated esophageal inflammation Clinical features * Dysphagia * Chest/epigastric pain * Reflux/vomiting * Food impaction * Associated atopy Diagnosis * Endoscopy & esophageal biopsy (≥15 eosinophils per high-power field) Treatment * Dietary modification * ± Topical glucocorticoids Most commonly affects younger men (age 20-30) and is associated with other atopic conditions (eg, asthma, **eczema**), classically presents with intermittent solid food dysphagia (often associated with eating meat) due to extensive eosinophilic infiltration of the mucosa. Other common manifestations include symptoms of refractory gastroesophageal reflux and chest/upper abdominal pain. Symptoms are due to esophageal inflammation triggered by food allergens, and patients frequently have **eczema** or other **allergic conditions (eg, asthma, rhinitis)**. Presentation typically includes dysphagia (ie, difficulty swallowing), mid-chest and epigastric pain, vomiting, and food impaction. Food refusal or a preference for soft foods is common in children. These symptoms can lead to weight loss. If not recognized early, EoE can progress to fibrosis, leading to **esophageal strictures** that result in progressive dysphagia and food impaction. The endoscopic appearance of EoE includes furrowing; small, whitish exudates; and multiple stacked, ringlike esophageal indentations (trachealization of the esophagus). The diagnosis is confirmed with esophageal biopsy demonstrating **≥15 eosinophils** per high-power field. Management includes dietary therapy (eg, allergen avoidance, elimination diet), proton pump inhibitors, and topical glucocorticoids(eg, fluticasone, budesonide).

Answer 5

Chronic gastroesophageal reflux disease (GERD) predisposes to Barrett's esophagus (intestinal metaplasia of the lower esophagus) and esophageal strictures. Both conditions are consequences of the body's reparative response to chronic gastric acid exposure and can occur simultaneously. Benign strictures affect 5%–15% of patients with GERD. Other causes of peptic strictures include radiation, systemic sclerosis, and caustic ingestions. Strictures typically cause slowly progressive **dysphagia to solid foods** without anorexia or weight loss. As they progress, they can actually block reflux, leading to improvement of heartburn symptoms. Strictures tend to appear as **symmetric, circumferential narrowing** on barium swallow. Nonetheless, in any case of stricture in the setting of Barrett's esophagus, **biopsy** is necessary to rule out adenocarcinoma. This is usually accomplished via **endoscopy** which may be diagnostic and therapeutic (**dilation** is performed if no malignancy is detected).

Answer 6

Presents with a sensation of food getting stuck in the esophagus (not throat) a few seconds after a swallow but does not cause difficulty initiating swallowing. **Dx:** **Esophageal motility studies** (manometry) and **upper gastrointestinal endoscopy** are typically used for evaluating. "Schotsky's ring" reflux **Tx: Baclofen**, diltiezam, **nitroglycerin**, nifedipine. Nissen fundoplication, myotomy

Answer 7

This is a motor disorder of the esophagus **Hx: Dysphagia for** **liquids AND solids**; also may be associated with chest pain. Heartburn or chest pain in achalasia is not caused by reflux but by fermentation of retained esophageal contents or esophageal muscle spasm. Patients with achalasia often regurgitate undigested food. **Dx: Manometry** shows elevated pressure and poor relaxation of the lower esophageal sphincter. In classic achalasia the contractions of the esophagus are weak, although a variant called vigorous achalasia is associated with large-amplitude prolonged contractions. **Tx:** Medications (nitrates, calcium channel blockers, botox injections into the LES) or physical procedures (balloon dilatation or surgical myotomy) that decrease LES pressure are the recommended treatments.

Answer 8

**Primary achalasia** (ie, loss of peristalsis in the distal esophagus with lack of lower esophageal sphincter relaxation) **Pseudoachalasia** due to esophageal cancer. Several clues point to pseudoachalasia (eg, narrowing of distal esophagus not due to denervation) caused by malignancy. **Dx: Endoscopic evaluation** can differentiate between achalasia and pseudoachalasia. In achalasia, this evaluation usually shows normal-appearing esophageal mucosa and a dilated esophagus with possible residual material; in addition, it is generally possible to easily pass the endoscope through the lower esophageal sphincter (unlike in malignancy).

Answer 9

Dysphagia for liquids and solids; also may be associated with chest pain; may be coincident with GERD

Answer 10

Etiology * **Instrumentation** (eg, endoscopy, TEE), trauma * Effort rupture (Boerhaave syndrome) * Esophagitis (infectious/pills/caustic) Clinical presentation * Chest/back &/or epigastric pain, systemic signs (eg, fever) * **Crepitus, Hamman sign (crunching sound on auscultation)** * **Pleural effusion with atypical (eg, 🔰green) fluid** Diagnosis * Chest x-ray or CT scan: widened mediastinum, pneumomediastinum, pneumothorax, pleural effusion * CT scan: esophageal wall thickening, mediastinal fluid collection * **Esophagography with 💦water-soluble contrast:** leak from perforation Management * NPO, IV antibiotics & proton pump inhibitors * **Emergency surgical consultation** Esophageal perforation is most often due to instrumentation; endoscopy, particularly when performed with additional interventions (eg, biopsy, cauterization, stricture dilation), is a common cause. Patients may develop severe chest pain (and/or back pain due to the esophagus's posterior anatomical location) and systemic findings (eg, fever) within hours of the procedure. A minority have **crepitus (subcutaneous emphysema) or crunching heard on auscultation (Hamman sign)**. Chest x-ray may reveal findings consistent with air/fluid leakage into the mediastinum (eg, pneumomediastinum, widened mediastinum) or thorax (eg, pneumothorax, pleural effusion). Visualization of contrast leaking from the esophagus into surrounding tissues confirms the diagnosis, by either **esophagography** or **CT scan using water-soluble contrast.** Barium contrast is more sensitive but can incite a granulomatous inflammatory response; it is used when water-soluble contrast esophagography is inconclusive. Esophageal perforation is a life-threatening condition. Therefore, management includes emergent surgical consultation, in addition to intravenous antibiotics and proton pump inhibitors. Surgical debridement and repair remain the mainstay of treatment, although select healthy patients (eg, limited leak, minimal symptoms, no signs of sepsis) may receive a trial of medical management.

Answer 11

Dysphagia or odynophagia; often in immunocompromised patients with candidal, CMV, or HSV esophagitis

Answer 12

Gastrointestinal neuropathy, often manifesting as gastroparesis, is another cause of frequent hospitalization in patients with advanced 🍭 diabetes. Gastroparesis should be suspected in a diabetic patient who has erratic glucose control with nonspecific gastrointestinal complaints and no other identifiable cause. Delayed gastric emptying (gastroparesis) is a common cause of recurrent vomiting, nausea, early satiety, and weight loss in poorly controlled diabetics. **Dx:** The best diagnostic test is a scintigraphic gastric emptying study, which will show delay in gastric emptying. **Tx:** Treatment includes withdrawal of aggravating drugs such as opiates and anticholinergics, good diabetes control, and drug therapy with **metoclopramide** or erythromycin.

Answer 13

Up to 60% of epigastric pain; Chronic or recurrent discomfort centered around the upper abdomen. Common causes of dyspepsia include nonsteroidal anti-inflammatory drugs, gastric or esophageal cancer, functional dyspepsia, gastroesophageal reflux disease (GERD), and symptomatic infection (eg, peptic ulcer disease [PUD]) with **Helicobacter pylori (a urease-producing organism).** **Hx:** According to the **Rome III (dyspepsia) criteria,** functional dyspepsia includes one or more of the following: (1) bothersome postprandial fullness, (2) early satiety, (3) epigastric burning, and (4) epigastric pain with: **Dx: lack of structural disease on upper endoscopy,** and those who do have abnormalities are found to have esophagitis. Therefore, predominant heartburn or regurgitation symptoms should be categorized as GERD rather than dyspepsia. To establish the diagnosis, these criteria should be met for 3 months, with symptom onset at least 6 months prior to diagnosis. **Upper endoscopy** is recommended in patietns with alarm features (onset after age 50 years; anemia; dysphagia; odynophagia; vomiting; weight loss; family history of upper gastrointestinal malignancy; personal history of peptic ulcer disease, gastric surgery, or gastrointestinal malignancy; and abdominal mass or lymphadenopathy on examination). **Tx:** Empiric therapy with a **proton pump inhibitor** (PPI) is the most cost-effective management strategy.

Answer 14

**Hx: Dysphagia** for solids (initially) and liquids (later), **weight loss;** often in patients with long-standing GERD; usually incurable by the time it presents clinically **Alarm symptoms** present including onset after age 50 years, brief history of symptoms, weight loss, nocturnal symptoms, family history of colon cancer, rectal bleeding, and recent antibiotic use. Patients with **Barrett's Esophagus** have more severe esophageal acid reflux than those with nonerosive reflux disease. BE is a **premalignant condition**; patients with BE have an estimated 30- to 50-fold increased risk of developing esophageal adenocarcinoma compared with those without BE and an annual incidence of esophageal adenocarcinoma of 0.5%. Approximately 10% of patients with chronic GERD symptoms have BE on upper endoscopy. Overall survival in patients with BE is comparable to that of age- and sex-matched populations. Adenocarcinoma accounts for less than 10% of the total mortality rate in patients with BE.

Answer 15

2%–29% of epigastric pain **Hx:** Burining chest pain, worse by recumbency, caffiene, or alcohol. **Atypical:** hoarseness, coughing, sore throat, stridor and nocturnal asthma. Can also mimic ischemic chest pain. **Dx:** The presence of heartburn, regurgitation, or both is sufficient to presumptively diagnose GERD PPI + lifestyle x 6 weeks; EGD; 24-hour pH-impedance monitor; manometry. **Esophageal pH monitoring** identifies the reflux of acid, and **impedance monitoring** detects reflux of other gastric contents in a small percentage of patients who have symptoms related to non-acid reflux. **Tx:** After cardiac causes have been excluded by comprehensive cardiac examination, an **8- to 10-week trial of proton pump inhibitor therapy** is reasonable before further testing in patients with noncardiac chest pain who do not have ❗**alarm symptoms** (dysphagia, odynophagia, weight loss, or gastrointestinal bleeding), * **Omeprazole (Prilosec) 20 mg QD** * **Ranitidine (Zantac)** If **metaplasia** use **high dose**; **dysplasia** do local **ablation**.

Answer 16

Mid-epigastric abdominal pain, nausea/vomiting, weight loss, and microcytic anemia (likely iron deficiency). Risk is greatest in those from Eastern Asia (eg, China), Eastern Europe, and the Andean portion of South America due to diets rich in salt-preserved food and nitroso compounds, which promote gastric injury and carcinogenesis. Helicobacter pylori infection, pernicious anemia, and smoking also increase risk. Most cases present late in the disease course when tumors have grown large enough to cause progressive epigastric abdominal pain, weight loss due to early satiety, and dysphagia or nausea/vomiting due to proximal stomach obstruction. Because friable tumor vessels often ooze blood into the gastric lumen, many patients develop iron deficiency anemia without overt signs of gastrointestinal bleeding ("slow bleed"). Metastases to the liver can also cause hepafmalttomegaly, elevated alkaline phosphatase/transaminases, and signs of liver failure (eg, hypoalbuminemia). **Dx:** Workup generally begins with **esophagogastroduodenoscopy** to visualize the stomach and to biopsy suspicious lesions. **Staging imaging** (eg, CT abdomen) is then usually required to evaluate for metastatic disease.

Answer 17

Chest or midepigastric pain, diaphoresis, shortness of breath; elevated cardiac enzymes; acutely abnormal electrocardiogram

Answer 18

**Acute cholangitis** **Pneumonia** **Acute viral hepatitis** **Acute alcoholic hepatitis** **Gonococcal perihepatitis (Fitz-Hugh–Curtis syndrome)** **Cholecystitis** **Others: PUD, perforated ulcer, pancreatitis, liver tumors, gastritis, hepatic abscess, choledocholithiasis, pyelonephritis, nephrolithiasis, appendicitis (especially during pregnancy); thoracic causes (e.g., pleurisy/pneumonia), PE, pericarditis, MI (especially inferior MI)**

Answer 19

**Hx: Charcot triad** (RUQ pain, fever, jaundice) or **Reynold pentad** (Charcot triad plus shock and mental status changes). **Dx:** A bilirubin \>4 mg/dL. AST and ALT may be \>1000 U/L; ALT usually \> AST; serum alkaline phosphatase elevation is common. **Biliary stasis** predisposes to AC, and the most common causes are due to bile duct obstruction from gallstones, malignancy, or stenosis. In the setting of stasis, the bile-blood barrier can be disrupted, allowing bacteria and toxins from the hepatobiliary system to translocate into the blood stream. **Tx:** Supportive care, broad-spectrum antibiotics, and biliary drainage, preferably by endoscopic retrograde cholangiopancreatography with sphincterotomy, are the mainstays of treatment. Other options for biliary decompression include percutaneous transhepatic cholangiography and open surgical decompression.

Answer 20

**Hx:** Epigastric and RUQ pain with **Murphy sign;** pain that radiates to right shoulder (scapula); **Dx:** Bilirubin \<4 mg/dL unless complicated by choledocholithiasis; AST and ALT levels may be minimally elevated; Leukocytosis. **RUQ Ultrasound: Pericholecystic fluid** and a **thickened gallbladder wall;** a sonographic Murphy sign (maximal tenderness directly over the visualized gallbladder) further supports the diagnosis. Less sensitive for choledocholithiasis or for complications (abscess, perforation, and pancreatitis); shows thickened gallbladder and pericholecystic fluid. **If ultrasonography is nondiagnostic,** cholescintigraphy (eg, hepatobiliary iminodiacetic acid **(HIDA scan)** is indicated. Nonvisualization of the gallbladder suggests cholecystitis. **_ERCP_** is the 🥇gold standard for diagnosis and treatment of **choledocholithiasis,** If bile duct stones are suspected, **magnetic resonance cholangiography (MRCP)** is preferred because it is more sensitive than ultrasonography and, unlike endoscopic retrograde cholangiopancreatography (ERCP), is noninvasive. **MRCP:** CBD stones. Less sensitive for stones in gallbladder, malignancy. **Asymptomatic Gallstones** An estimated 60% to 80% of gallstones are asymptomatic. Over a 20-year period, 50% of patients remain asymptomatic, 30% develop biliary colic, and 20% develop more significant complications. **Tx: Observation** is recommended for adult patients with asymptomatic gallstones. The possible exceptions to this recommendation are groups at higher risk for gallbladder carcinoma, such as patients with a calcified (porcelain) gallbladder, certain American Indian populations, and patients with gallstones larger than 3 cm. **Tx:** Symptoms often subside within a few days with volume resuscitation, antibiotics, and pain medications. However, **early cholecystectomy (within 72 hours⏲)** reduces disease duration, duration of hospitalization, and mortality when compared to delayed cholecystectomy (\>7 days after hospitalization). Laparoscopic cholecystectomy is the surgical procedure of choice in patients without contraindications. Early cholecystectomy is also advised for patients with other complications of gallstones, such as gallstone pancreatitis. **Acalculous cholecystitis** is an acute inflammation of the gallbladder in the absence of gallstones. Acalculous cholecystitis is most often seen in hospitalized patients who are **critically ill.** Common predisposing conditions include recent surgery (particularly cardiopulmonary, aortic, or abdominal), severe trauma, extensive burns, sepsis or shock, prolonged fasting or total parenteral nutrition, or critical illness requiring mechanical intubation. These conditions likely cause gallbladder stasis or ischemia with local inflammation that can lead to gallbladder distension, necrosis, and secondary bacterial infection. **Cx: Porcelain gallbladder** is a term used to describe the calcium-laden gallbladder wall with **bluish color and brittle consistency** often associated with chronic cholecystitis. The pathogenesis of the condition remains unclear, but it is thought that calcium salts are deposited intramurally due to the natural progression of chronic inflammation or chronic irritation from gallstones. Plain x-rays can show a rimlike calcification in the area of the gallbladder, and CT scan typically reveals a calcified rim in the gallbladder wall with a central bile-filled dark area. Porcelain gallbladder has been associated with increased risk for **gallbladder adenocarcinoma** (2%-5% in some studies). **Emphysematous cholecystitis (EC)** is characterized by fever, right upper quadrant (RUQ) pain, and **gas** in the gallbladder wall or surrounding tissue. Unlike uncomplicated acute cholecystitis, EC is a **surgical emergency** and warrants immediate intervention. In addition to emergency cholecystectomy, management involves **broad-spectrum antibiotics** (eg, **piperacillin-tazobactam, ertapenem**) and **bile culture**. EC occurs when gas-forming organisms such as Clostridium infect damaged or ischemic tissue in the gallbladder wall, with bacterial exotoxins resulting in hemolysis, tissue necrosis, and septic shock; if untreated, EC progresses to gangrenous cholecystitis and gallbladder perforation in most patients. Risk factors include relative immunosuppression (eg, age \>50, diabetes mellitus) and vascular disease (eg, compromised cystic artery blood supply, atherosclerosis). In addition to pain and guarding, crepitus in the RUQ may occasionally be present. Typical laboratory findings include leukocytosis with left shift and small elevations in aminotransferases. With clostridial infection, a mild to moderate unconjugated hyperbilirubinemia can occur secondary to hemolysis. Imaging may demonstrate pneumobilia (air within the hepatobiliary system), air-fluid levels in the gallbladder, and gas within the gallbladder wall or surrounding tissue. Unlike other forms of acute cholecystitis, ultrasound is less sensitive due to the modality's poor visualization of air-filled structures, and extensive gas in the gallbladder wall may be falsely interpreted as being due to bowel loops. CT imaging is preferred due to the improved ability to delineate air-filled structures.

Answer 21

Common cause of chronic hepatitis and cirrhosis. **Hx:** History of excessive alcohol consumption, low-grade fever, jaundice, a tender enlarged liver. **Dx:** AST/ALT ratio \>2. Improvement with alcohol cessation. **Tx:** The goals of therapy for cirrhosis are to slow the progression of the underlying liver disease, prevent further injury to the liver, prevent and treat complications (esophageal varices, ascites, **hepatic encephalopathy**, hepatocellular carcinoma), and evaluate the patient for liver transplantation. Protein-calorie malnutrition and hypermetabolism are common in patients with cirrhosis, and nutritional assessment is important. Patients with alcoholism should receive **folate** and **thiamine** supplementation, and patients with ascites should have dietary sodium restriction (\<2 g/day). While patients with mild to moderate alcoholic hepatitis have a reasonably good prognosis with alcohol abstinence and **supportive care**, those with severe hepatitis have a high short-term mortality rate and may benefit from treatment, which may include glucocorticoids and pentoxifylline in addition to supportive measures. The **Maddrey discriminant function (DF) score,** which helps to identify patients whose short-term survival is improved by glucocorticoid therapy, is calculated as follows: **DF** = 4.6 (Prothrombin time [s] − Control prothrombin time [s]) + Serum bilirubin (mg/dL) Patients with a **DF score \>32** have a \>50% short-term (30-day) mortality risk. Such patients are candidates for therapy with **prednisone**. **Pentoxifylline** may be used as an alternative for patients with contraindications or early renal failure. The **Lille score** is another method to determine if patients with alcoholic hepatitis are responding to glucocorticoid therapy. It combines six variables: age, renal insufficiency (Cr \>1.3 or creatinine clearance \<40 mL/minute), albumin, prothrombin time, bilirubin, and evolution of bilirubin at day 7 (bilirubin at day 7 – bilirubin at day 0). A score \>0.45 suggests that a patient is not responding to glucocorticoid therapy. Cx: **Sialadenosisis** commonly found in patients with advanced liver disease (eg, alcoholic and nonalcoholic cirrhosis). It is also seen in patients with altered dietary patterns or malnutrition (eg, diabetes, bulimia). Sialadenosis is a benign, noninflammatory swelling of the salivary glands. It is associated with abnormal autonomic innervation of the glands, with accumulation of secretory granules in acinar cells.

Answer 22

Typically young women (90%) with fatigue and jaundice. **Dx:** Aminotransferase elevations; hypergammaglobulinemia and other autoimmune diseases may be present. Look for specific autoantibodies (ANA, ASMA); **AST:ALT ratio less than 2.**

Answer 23

Typical biliary pain and **no gallstones** on imaging studies. If necessary, diagnosis made by aspiration of gallbladder bile from the duodenum or directly from the gallbladder during ERCP and microscopic examination. May cause pain, cholecystitis, or pancreatitis. Treated with cholecystectomy.

Answer 24

**Hx:** Abdominal pain with normal ultrasonographic imaging. Typical biliary pain, no gallstones on imaging studies. Symptoms similar to those of biliary colic. The presence of proteins and fatty acids in the duodenum acts as a stimulus for release of cholecystokinin (CCK), which in turn stimulates the contraction of the gallbladder. In patients on total parenteral nutrition or prolonged fasting, the normal stimulus for CCK release and gallbladder contraction is absent. This leads to biliary stasis and promotes the formation of bile sludge and gallstones. Small-bowel (ileal) resection also contributed to the formation of gallstones. Decreased enterohepatic circulation of bile acids results in altered hepatic bile composition, which becomes supersaturated with cholesterol and promotes gallstone formation. **Dx:** CCK-induced gallbladder ejection fraction \<35%–40% on cholescintigraphy. Symptoms usually relieved with cholecystectomy. Sphincter of Oddi manometry may be required to diagnose sphincter of Oddi dysfunction.

Answer 25

Exposure history most commonly alcohol but may be medications (methotrexate, amiodarone, high-dose vitamin A) or chemicals (hydrocarbons). Long-term TPN can lead to cirrhosis. **Acetaminophen toxicity** results from overproduction of the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI), which leads to hepatic necrosis. NAPQI is normally safely detoxified through glucuronidation in the liver, but this pathway becomes overwhelmed in overdose. **Chronic alcohol use** is thought to potentiate acetaminophen hepatotoxicity by depleting glutathione levels and impairing the glucuronidation process. On the other hand, N-acetylcysteine increases glutathione levels and binds to NAPQI, so it is an effective antidote for acetaminophen overdose when given early. Doses of greater than 3 g/d are needed to cause hepatotoxicity (typically results in serum AST and ALT values greater than 5000 U/L). **Tx:** Drug discontinuation.

Answer 26

Can cause anaphylaxis with eventual shock. However, an echinococcal cyst usually appears on abdominal CT as a cystic liver lesion (sometimes with calcifications) without gallbladder involvement. It would be unlikely in a patient who has never traveled outside the United States.

Answer 27

**Child-Pugh classification:** The Child-Pugh classification has been used to assess the risk of non-shunt operations in patients with cirrhosis. Patients with a score of 5 or 6 have Child-Pugh **class A cirrhosis** (well-compensated cirrhosis), those with a score of 7 to 9 have Child-Pugh **class B cirrhosis** (significant functional compromise), and those with a score of 10 to 15 have **Child-Pugh class C** cirrhosis (decompensated cirrhosis). **MELD score:** Another model to predict prognosis in patients with cirrhosis is the MELD score. It is based upon bilirubin levels, creatinine, INR, and the etiology of cirrhosis. The MELD score has been adopted for use in prioritizing patients awaiting **liver transplantation** and has an expanding role in predicting outcomes in patients with liver disease in the non-transplantation setting. **FIB-4 index:** The FIB-4 index combines biochemical values (platelet count, ALT, and AST) and age. It had good predictive accuracy for **advanced fibrosis** in at least two studies involving patients with chronic HCV. FIB-4 values have also been associated with the risk of developing hepatocellular carcinoma (HCC) among patients who consume alcohol.

Answer 28

**"Acute liver Failure"** is defined as severe acute liver injury without underlying liver disease and is characterized by elevated aminotransferases (often \>1,000 U/L), hepatic encephalopathy, and synthetic liver dysfunction (defined as prolonged prothrombin time [PT] with INR \>1.5). **Tx:** Approximately only half of patients with ALF will survive without liver transplantation. **Dx:** Typically presents with evidence of liver dysfunction in addition to the disturbance of bilirubin metabolism. Findings often include an increase in coagulation time (as measured by the international normalized ratio) due to a decrease in liver production of coagulation factors and a low serum albumin level due to decreased liver albumin production. **Hyperestrinism** is due to impaired hepatic metabolism of circulating estrogens, a process that begins in the cytochrome P450 system. Circulating estrogens affect vascular wall dilation. **Spider angioma** consists of a central, dilated arteriole surrounded by smaller radiating vessels. **Palmar erythema** is a result of increased normal speckling of the palm due to increased vasodilation, especially at the thenar and hypothenar eminences. Other manifestations of hyperestrinism in patients with cirrhosis include gynecomastia, testicular atrophy, and decreased body hair in males. **Caput medusae** arise from the dilation of superficial veins on the abdominal wall due to portal hypertension (PH). PH results from increased resistance to portal flow at the sinusoids and leads to increased pressure at the portosystemic collateral veins in the anterior abdomen, rectum, and distal esophagus. **Hepatic encephalopathy (HE)** may also be present because of the inability of the liver to clear toxic metabolic by-products from the blood. ❗P**recipitating factors** for HE include azotemia, acute liver decompensation, use of sedatives or opioids, GI hemorrhage, hypokalemia, constipation, infection, a high-protein diet, and recent placement of a **portosystemic shunt (TIPS)**. **_🍌Hypokalemia** can exacerbate **HE** as the resultant intracellular acidosis (excreted intracellular potassium replaced by hydrogen ions to maintain electroneutrality) causes increased NH3 production (glutamine conversion) in renal tubular cells. **Tx:** repletion **Metabolic alkalosis (elevated bicarbonate)** can also exacerbate HE as it promotes conversion of ammonium (NH4+), which cannot enter the CNS, to NH3, which can enter the CNS **Serum binding proteins for thyroid hormone**s (eg, thyroxine-binding globulin, transthyretin, albumin, lipoproteins). Cirrhosis leads to decreased synthesis of these proteins, which lowers the total triiodothyronine (T3) and thyroxine (T4) in circulation; however, free T3 and T4 levels are unchanged, and TSH will be normal, reflecting a euthyroid status. **Tx: Lactulose**; If not recognized and treated, encephalopathy progresses from subtle findings, such as **reversal of the sleep-wake cycle** or mild mental status changes, to **irritability, confusion, slurred speech**, and ultimately **coma**. There can be multiple inciting causes of encephalopathy in patients with cirrhosis, including dehydration, infection (especially **s**pontaneous **b**acterial **p**eritonitis), dietary indiscretions, gastrointestinal bleeding, and medications. **Tx:** All patients with cirrhosis undergo **screening upper endoscopy** to detect large **esophageal varices**. Small varices are usually less than 5 mm in diameter; **large** varices are **\> 5 mm**. * **Grade 1** – Small, straight esophageal varices. * **Grade 2** – Enlarged, tortuous esophageal varices occupying less than one third of the lumen. * **Grade 3** – Large, coil-shaped esophageal varices occupying more than one third of the lumen. **Tx:** Initial treatment of suspected variceal bleeding includes **volume resuscitation**, through 2 to 3 large-bore peripheral intravenous lines. **Prophylactic antibiotics** (eg, ceftriaxone) should be given to cirrhotic patients with gastrointestinal bleeding to decrease infectious complications, recurrent bleeding, and mortality. **Somatostatin analogues** (eg, **octreotide**) inhibit the release of vasodilator hormones, which leads indirectly to splanchnic vasoconstriction and decreased portal flow. **Urgent endoscopy** (within 12 hours) can diagnose **and treat** (eg, endoscopic band ligation, sclerotherapy) active bleeding. **Uncontrollable bleeding** require **temporary balloon tamponade (eg, Sengstaken-Blakemore, Minnesota, Linton-Nachlas tubes)** as a short-term measure until more definitive therapy, including transjugular intrahepatic portosystemic shunt (TIPS) or shunt surgery. Patients without further bleeding after endoscopy can be monitored and receive **secondary prophylaxis (beta blocker)** with repeat endoscopic band ligation 1-2 weeks later. When large varices are present, the next step in management is use of nonselective **β-blocker** therapy or **_endoscopic variceal band ligation_** as primary prophylaxis to prevent variceal hemorrhage. Patients with contraindications to β-blocker therapy, such as asthma or resting bradycardia, can be offered endoscopic ligation. **Hepatorenal Syndrome** Arterial vasodilatation in the splanchnic circulation, which is triggered by portal hypertension, appears to play a central role in the hemodynamic changes and the decline in renal function in cirrhosis. **Type 1:** 2x increase in serum creatinine \>2.5 mg/dL during a period of less than 2 weeks. Urine output less than 400 to 500 per day is common. **Type 2:** impairement is less servere than above. Patients typically have ascities resistant to diuretics. **Tx:** Midodrine, Octreotide **Hepatopulmonary syndrome** results from intrapulmonary vascular dilations. Patients frequently have evidence of **platypnea** (increased dyspnea while upright) or **orthodeoxia** (oxygen desaturation while upright). **Tx:** Liver Transplant Cirrhosis caused by **hepatitis C** is the most common cause for liver transplantation in the United States. **Absolute contraindications:** Portal vein thrombosis, severe medical illness, malignancy, hepatobiliary sepsis, or lack of patient understanding. **Relative contraindications:** Active alcoholism (\<6 mo), HIV or hepatitis B surface antigen positivity, extensive previous abdominal surgery, and a lack of a personal support system.

Answer 29

HCC usually arises in the setting of chronic liver inflammation due to **alcohol abuse, environmental toxins** (eg, **aflatoxin**, betel nut chewing), or **viral hepatitis** (eg, **hepatitis B** virus [HBV], **hepatitis C** virus [HCV]). Incidence is greatest in **Asia (eg, Vietnam), Africa**, and the **Middle East** due to high rates of underlying HBV/HCV infection. In these regions, viral transmission often occurs via the maternal-to-child route, leading lifelong viral hepatitis in the newborn (and increased risk of cirrhosis/HCC later in life). Screening for HCC every 6 to 12 months is recommended for patients with cirrhosis of any cause and for patients with chronic hepatitis B who are considered at high risk (active inflammation and age \>40 years in men and \>50 years in women; a family history of HCC; specific ethnic groups [Asians, African/North American blacks]). **Hx:** Patients with HCC often develop systemic (eg, weight loss, fatigue), abdominal (eg, right upper quadrant pain, early satiety), or metastatic (eg, bone pain) manifestations. Liver function tests may be normal or elevated; alkaline phosphatase is occasionally dramatically elevated due to **osteoblastic bone metastases**. Significant elevation in alpha-fetoprotein raises strong suspicion for HCC but is present only in ~50% of cases. **Dx:** HCC derives its blood supply by neovascularization, whereby the tumor develops a new blood supply fed through small branches of the hepatic artery. It is this characteristic vascular supply that helps identify potential cancers on contrast-enhanced imaging, such as triple-phase CT and gadolinium-enhanced magnetic resonance imaging (MRI). Current guidelines recommend the use of ultrasonography to screen for HCC, followed by CT or MRI to better define any abnormalities suggestive of HCC. **Alpha-fetoprotein (AFP)**, a glycoprotein produced by the fetal liver and yolk sac, is elevated in **50%** of cases; therefore, AFP can serve as an important diagnostic clue (when elevated) but cannot be used to rule out the diagnosis. Triple phase arterial contrast CT scan of the abdomen is diagnostic in most cases. The presence of elevated alpha-fetoprotein (AFP), a glycoprotein produced by the fetal liver and yolk sac, raises strong suspicion for **primary testicular (yolk sac) or liver (hepatocellular carcinoma [HCC])** cancer

Answer 30

Precipitating factors * Drugs (eg, sedatives, narcotics) * Hypovolemia (eg, diarrhea) * **Electrolyte changes (eg, hypokalemia)** * ↑ Nitrogen load (eg, GI bleeding) * Infection (eg, pneumonia, UTI, SBP) * Portosystemic shunting (eg, TIPS) Clinical presentation * Sleep pattern changes * Altered mental status * Ataxia * Asterixis Treatment * Correct precipitating causes (eg, fluids, antibiotics) * ↓ Blood ammonia concentration (eg, lactulose, rifaximin) HE refers to impaired central nervous system (CNS) function in patients with cirrhosis and is due in part to the neurotoxicity from ammonia (NH3) in the setting of impaired liver function. **Hypokalemia**, which can exacerbate HE as the resultant intracellular acidosis (excreted intracellular potassium replaced by hydrogen ions to maintain electroneutrality) **causes increased NH3 production** (glutamine conversion) in renal tubular cells **Metabolic alkalosis (elevated bicarbonate)**, which can also exacerbate HE as it **promotes conversion of ammonium (NH4+),** which cannot enter the CNS, to NH3, which can enter the CNS As a result, patients with HE and hypokalemia require **prompt potassium repletion** in addition to intravascular volume repletion. Disaccharides (eg, lactulose, lactitol) are also administered to lower NH3 levels.

Answer 31

A benign regenerative liver nodule common in women age 20-50. Most cases of FNH are asymptomatic and are discovered during abdominal imaging for other conditions. Lesions tend to be ⚪ **well-circumscribed,** solitary, and \<5 cm in size; they characteristically have a **central, stellate scar 🌟,** which surrounds a large congenital arterial anomaly that sends arterial branches to the periphery. Imaging with triphasic, helical CT scan (which evaluates the mass during different phases of vascular contrast) generally reveals a hyperdense lesion (ie, filled with contrast during hepatic arterial phase) and a central scar. Because FNH **does not generally grow over time,** undergo malignant transformation, or rupture, **treatment is rarely required.** Oral contraception is not believed to worsen FNH; therefore, contraception usually can be continued (in contrast to hepatic adenoma).

Answer 32

Hepatic adenomas generally arise in young women who have been on prolonged estrogen-based **oral contraception.** Epidemiology * Benign epithelial liver tumor * Primarily young women on **oral contraception** Manifestations * Often asymptomatic (incidentally found) * Episodic right upper quadrant pain Imaging * Solitary, solid lesion in right lobe of liver * Multiple lesions occasionally occur Treatment * Asymptomatic & **\<5 cm – 🛑 stop oral contraception** * Symptomatic or **\>5 cm – 🔪 surgical resection** Complications * Malignant transformation (~10%) * **Rupture** & hemorrhagic shock Although considered benign and often discovered incidentally on imaging for other conditions, hepatic adenoma can cause life-threatening complications such as malignant transformation and rupture. **Cx: Rupture s**hould be suspected in those with sudden-onset, severe right upper quadrant pain who have signs of hemorrhagic shock; low-grade fever and mild leukocytosis also sometimes occur due to peritoneal irritation from blood in the abdominal cavity. Ultrasound generally reveals a single, solid liver lesion (usually in the right hepatic lobe) and **free fluid (blood) in the abdomen**. Urgent circulatory support and surgical intervention are required to prevent death.

Answer 33

The condition is characterized by **triglyceride accumulation** in the hepatocytes (steatosis). The underlying pathophysiology is closely linked to insulin resistance and hence to **obesity, diabetes, hyperlipidemia and the metabolic syndrome**. Most cases are discovered incidentally because of elevated transaminases. Patients may have nonspecific right upper quadrant discomfort and hepatomegaly. Spectrum of liver disease ranges from steatosis to steatohepatitis to cirrhosis. Perhaps most common cause of chronic hepatitis in United States. NAFL is associated with **mAcrovesicular** accumulation of fat in the liver. NAFLD can be due to **increased transport of free fatty acids (FFA) from adipose tissue to the liver**, decreased oxidation of FFA in the liver, or **decreased clearance of FFA** from the liver (due to decreased VLDL production). [Microvesicular fat is seen in the acute life-threatening conditions of acute fatty liver of pregnancy and Reye syndrome.] It is frequently **related to peripheral insulin resistance** leading to **increased peripheral lipolysis, triglyceride synthesis, and hepatic uptake of fatty acids**. Hepatic FFA increases oxidative stress and production of proinflammatory cytokines (eg, tumor necrosis factor-alpha). **Hx:** Usually results from insulin resistance and the metabolic syndrome (obesity, diabetes mellitus, dyslipidemia, and hypertension). **Dx:** If **hepatocellular necrosis** is present, the condition is termed **nonalcoholic steatohepatitis (NASH).** NASH may be inferred in patients who have the metabolic syndrome and elevated serum aminotransferase levels in the absence of other causes of liver disease. Liver ultrasonography shows fatty infiltration. Liver biopsy confirms NASH and identifies the degree of hepatic inflammation and fibrosis. This condition is histologically similar to alcoholic hepatitis, and increasing evidence suggests that it too is a precirrhotic condition. **Tx:** The mainstay of treatment of NAFLD and NASH is weight loss and management of comorbidities.

Answer 34

Skin * **Hyperpigmentation (bronze diabetes)** Musculoskeletal * Arthralgia, arthropathy & chondrocalcinosis Gastrointestinal * Elevated hepatic enzymes with hepatomegaly (early), cirrhosis (later) & increased risk of hepatocellular carcinoma Endocrine * Diabetes mellitus, **secondary hypogonadism** & hypothyroidism Cardiac * Restrictive or dilated cardiomyopathy & conduction abnormalities Infections * Increased susceptibility to Listeria, Vibrio vulnificus & Yersinia enterocolitica Hemochromatosis is an autosomal recessive condition that causes increased intestinal absorption of iron and excessive total body iron stores. The cause is a defect in the HFE or related gene. It affects Caucasians most frequently at a rate of about 1 in 250 persons. The increased total body iron leads to deposits in various organs (eg, **liver, pancreas**), resulting in multisystem organ damage. Disease progression typically requires decades of increased iron deposition. Consequently, patients tend to present in their 30s to 50s, with women presenting later due to therapeutic iron loss through menstruation. Most patients with HH are diagnosed early in the disease due to elevated liver enzymes on routine laboratory studies. However, continued iron deposition can cause hepatic fibrosis and cirrhosis, **skin pigmentation** (sun-exposed areas, scars, genitalia), **diabetes mellitus** **("bronze diabetes")**, **arthropathy**, and **hypogonadism (diminished libido, erectile dysfunction [ED])**. Diabetes occurs secondary to direct damage to the pancreas by iron deposition. The initial evaluation of HH commonly shows elevated **iron studies**. Initial screening involves transferrin saturation (iron/total iron binding capacity) and ferritin levels. A **transferrin** **saturation \> 45%** or a **ferritin \>** **150** would be consistent with the diagnosis and would suggest the need for referral and genetic testing. Patients with HH have an approximate 20-fold increased risk for **hepatocellular cancer (HCC),** accounting for 45% of deaths in HH patients.

Answer 35

Progressive bile duct inflammation, destruction, and ultimately **fibrosis of both the intrahepatic and extrahepatic bile ducts**, which leads to cirrhosis. **Hx:** Typically men in their late 30s who are asymptomatic **(incidental finding of elevated alkaline phosphatase)**, particularly in patients with established ulcerative colitis. The most common symptoms of PSC are pruritus and fatigue; as the disease progresses, most patients develop jaundice. Diagnosis usually by endoscopic cholangiography. **Dx:** When patients with PSC are found to have acute worsening of liver chemistry test results (markedly elevated ALP level and mildly elevated aminotransferase levels), acute worsening of symptoms, or a new dominant stricture noted on cholangiography, the possibility of cholangiocarcinoma should be considered. The diagnosis of PSC depends on detecting multifocal strictures alternating with normal, dilated segment of the bile ducts leading to a “beaded” pattern on cholangiographic imaging. Ulcerative colitis is an independent risk factor for development of colorectal cancer, and patients with both ulcerative colitis and PSC may represent a distinct phenotype of disease with a particularly high rate of colorectal cancer.

Answer 36

Pathogenesis * Autoimmune destruction of **intrahepatic bile ducts** Clinical features * Affects middle-aged women * Insidious onset of **fatigue & pruritus** * Progressive jaundice, hepatomegaly, cirrhosis * Cutaneous **xanthomas & xanthelasmas** Laboratory findings * Cholestatic pattern of liver injury (↑↑ alkaline phosphatase, ↑ aminotransferases) * **Antimitochondrial antibody** * Severe hypercholesterolemia Treatment * **Ursodeoxycholic acid** (delays progression) * Liver transplantation for advanced disease Complications * Malabsorption, fat-soluble vitamin deficiencies * Metabolic bone disease (osteoporosis, osteomalacia) * Hepatocellular carcinoma PBC is a chronic liver disease characterized by autoimmune destruction of the **intrahepatic bile ducts** with resulting cholestasis. A chronic, progressive liver disease characterized by cholestasis with autoimmune destruction of **intrahepatic bile ducts.** **Hx:** Typically **women in their 50s** who are often asymptomatic at diagnosis **(incidental finding of elevated 🔰alkaline phosphatase).** It presents as chronic cholestasis with **fatigue**, **pruritus** without rash, hyperpigmentation, and sometimes xanthomas. As the disease progresses, jaundice, hepatomegaly, steatorrhea, and portal hypertension may develop. Additional complications can include severe **hyperlipidemia (with xanthelasma)** and metabolic bone disease. PBC is often associated with other autoimmune disorders (eg, autoimmune thyroid disease). **Dx: Ultrasound** to look for intrahepatic cholestasis. Most patients have **antimitochondrial antibodies** and elevated serum IgM, γ-glutamyl transferase, and ALP levels; aminotransferase levels also may be elevated. **Ultrasonography** should be used to exclude extrahepatic bile duct obstruction. PBC frequently is associated with other autoimmune disorders, such as hypothyroidism, Sjögren syndrome, sicca syndrome, and systemic sclerosis. **Tx: Ursodeoxycholic acid (UDCA)** is used in a number of cholestatic disorders and is the drug of choice in PBC. UDCA is a hydrophilic bile acid that decreases biliary injury by the more hydrophobic endogenous bile acids. It also increases biliary secretion and may have additional anti-inflammatory and immunomodulatory effects. UDCA delays histologic progression in PBC and may improve symptoms and possibly survival. It should be initiated as soon as the diagnosis is made, even in asymptomatic patients. Treatment is less effective in advanced disease, and many patients will go on to require **liver transplantation**.

Answer 37

**Color** * **Bloody**: Trauma, malignancy, TB (rarely) * **Milky**: Chylous, pancreatic * **Turbid**: Possible infection * **Straw** **color**: Likely more benign causes **Neutrophils** * \<250/mm³: No peritonitis * ≥250/mm³: Peritonitis (secondary or spontaneous bacterial) **Total protein** * ≥2.5 g/dL (high-protein ascites) * CHF, constrictive pericarditis, peritoneal carcinomatosis, TB, Budd-Chiari syndrome, fungal (eg, coccidioidomycosis) * \<2.5 g/dL (low-protein ascites) * Cirrhosis, nephrotic syndrome **SAAG** * ≥1.1 g/dL (indicates portal hypertension) * Cardiac ascites, cirrhosis, Budd-Chiari syndrome * \<1.1 g/dL (absence of portal hypertension) * TB, peritoneal carcinomatosis, pancreatic ascites, nephrotic syndrome **Dx:** **🧪 Cell count and differential** **\>250/µL neutrophils** diagnostic for ❗ **Spontaneous Bacterial Peritonitis (SBP)** with infection most commonly from enteric gram negative rods. Treatment should be initiated immediately to cover gram negative organisms. Standard antibiotic therapy is a 🌼**fluoroquinolone** or **third-generation cephalosporin** for 7 to 10 days. **Spontaneous bacterial peritonitis (SBP)** is the occurrence of bacterial infection in preexisting ascitic fluid without bowel wall perforation. It is almost always caused by a **single species** (isolation of multiple species would suggest a bowel wall perforation). The addition of albumin to antibiotic therapy has been shown to improve survival. **🧪 Albumin level (The serum albumin should be drawn at the same time of the procedure to calculate the SAAG)** **S**erum **A**scities **A**lbumin **G**radient (**SAAG**) is important in determining the etiology of the underlying ascites. It is calculated by subtracting the **ascitic fluid _⚪albumin** concentration from the **serum _⚪albumin** level (3.2 mg/dL – 1.0 mg/dL = 2.2 mg/dL). **SAAG ≥ 1.1 g/dL** 97% accurate for diagnosing ascites caused by **portal hypertension** and points to underlying**🐄** **liver (cirhosis, alk hep, hepatic metastasis, budd-chiari, protal vein thrombosis) or 🧡 cardiac disease (heart failure, constricticve pericarditis)**. **SAAG \< 1.1** (**Peritoneal 💜TB,** **peritoneal 🦀carcinomatosis, serositis,** 🧽 **Pancreatitis**, ⚪**nephrotic syndrome**) **🧪 Total protein** **\>2.5 g/dL (high-protein ascities)[CHF, constrictive pericarditis, TB, budd chiari, fungal)** \<2.5 g/dL identify patients at high risk for SBP (cirrhosis, nephrotic syndrome) **🧪 Gram stain and Culture (in blood culture bottles)** Used to identify causative organisms of SBP **Glucose** Low glucose suggests peritonitis caused by infection, bowel perforation, or tumor **Lactate dehydrogenase (LDH)** An ascitic-serum LDH ratio \>1 suggest peritonitis caused by infection, bowel perforation, or tumor **Acid-fast bacilli smear and culture** Smear has very low sensitivity for tuberculous (TB) peritonitis; culture sensitivity approximately 50% **Triglycerides 🔰** Chylous ascites **Amylase** Elevated in ascites caused by 🧽 **pancreatitis** **Cytology** Used when 🦀**malignant** ascites is suspected; sensitivity, 58%–75%

Answer 38

Clinical presentation * Temperature \>37.8 C (100 F) * Abdominal pain/tenderness * Altered mental status (abnormal connect-the-numbers test) * Hypotension, hypothermia, paralytic ileus with severe infection Diagnosis from ascitic fluid * PMNs \>250/mm3 * Positive culture, often gram-negative organisms (eg, Escherichia coli, Klebsiella) * Protein \<1 g/dL * SAAG \>1.1 g/dL Treatment * Empiric antibiotics - third-generation cephalosporins (eg, cefotaxime) * Fluoroquinolones for SBP prophylaxis Spontaneous bacterial peritonitis (SBP) is an ascitic fluid infection without an obvious intraabdominal surgical etiology. SBP is most likely due to either intestinal bacterial translocation directly into the ascitic fluid or hematogenous spread to the liver and ascitic fluid (due to other bacterial infections). Patients with cirrhosis are often relatively hypothermic, and any temperature ≥37.8 C (100 F) warrants investigation. Other manifestations of SBP may include diffuse abdominal discomfort/tenderness and/or mental status changes. The Reitan trail test, a timed connect-the-numbers test similar to children's connect-the-dots pictures, is excellent for use in detecting subtle mental status changes sometimes present in patients with cirrhosis and SBP. Hypotension, hypothermia, or paralytic ileus (dilated loops of bowel on x-ray) indicate severe SBP. As the vast majority of cases of SBP are associated with cirrhosis, the serum-ascites albumin gradient (SAAG) is usually ≥1.1 g/dL (a SAAG \<1.1 g/dL makes SBP unlikely). Ascitic fluid with a polymorphonuclear leukocyte (PMN) count ≥250/mm3 and positive peritoneal fluid culture confirm the diagnosis.

Answer 39

At least five distinct causes. Determined by serologic testing for hepatitis A, B, C, D, and E and confirmation of viral replication of hepatitis B and C. RIBA for HCV infection may also be used for confirmation.

Answer 40

Since the introduction of routine hepatitis A vaccination in the United States, infection rates have fallen significantly, but disease transmission remains a risk for a number of groups, including international travelers, men who have sex with men, illicit drug users, and those with household or sexual contact with infected persons. Transmission occurs most frequently via the fecal-oral route, although sexual and blood-borne transmission can also occur. Hepatitis A typically is associated with an abrupt onset of constitutional symptoms, such as fatigue, anorexia, malaise, nausea, and vomiting. Low-grade fever and right upper quadrant pain often are present as well. **Dx:** Markedly elevated transaminases, positive hepatitis A IgM antibody [Ab], negative hepatitis A IgG Ab. Confirm the diagnosis with serologic testing, specifically IgM antibody to HAV. In most patients, IgM antibody is detectable by the time a person is symptomatic and becomes undetectable by 6 months. The IgG antibody indicates prior infection and immunity; there is no chronic state of hepatitis A. Serum AST and ALT \> 500 U/L, often greater than 1000 U/L; ALT \> AST **Postexposure prophylaxis** with hepatitis A vaccine or hepatitis A immune globulin should be considered in a number of groups, including: **Close personal contacts** (eg, sexual contacts, household contacts) of hepatitis A-infected patients Child care center contacts (eg, staff and children) where staff, children, or household contacts of attendees have been infected **Food preparation workers** whose coworkers have been infected Prophylaxis should be given within 2 weeks of exposure; in general, younger patients (age \<40) should receive **hepatitis A vaccine**, whereas older patients (age \>41) should receive **hepatitis A immune globulin.**

Answer 41

Inactive carrier state there would be no evidence of active viral replication with circulating viral DNA) **Chronic HBV infection:** **Immune-tolerant** is identified by the presence of a circulating viral level in the absence of markers of liver inflammation. This pattern typically occurs in patients born in hepatitis B–endemic areas such as Southeast Asia or Africa in whom HBV was likely acquired perinatally. As long as patients maintain normal serum aminotransferase levels, they are at low risk for progression of liver disease. **A “window period”** exists when HBsAg levels have fallen but antibody to HBsAg (anti-HBs) has not yet become detectable; diagnosis is then based on the presence of antibody to hepatitis B core antigen (anti-HBc [IgM]). The first serologic marker to appear in the serum with **acute hepatitis B** is HBsAg, which appears usually 4-8 weeks after infection. IgM anti-HBc appears shortly thereafter, which is around the time clinical symptoms occur and patients develop elevations in hepatic aminotransferase levels (often \>25 times the normal limit). Test patients with evidence of chronic liver disease for chronic hepatitis B. Also test patients with glomerulonephritis, **polyarteritis nodosa, or cryoglobulinemia** because these are extrahepatic manifestations of chronic hepatitis B. **Tx:** Patients with chronic hepatitis B and a circulating viral level may show evidence of liver inflammation, evidenced by persistently elevated serum aminotransferase levels indicating active hepatitis. In these patients, liver biopsy should be considered and treatment should be initiated if significant inflammation or progressive liver injury is seen.

Answer 42

Hepatitis C infection is often progressive and may result in cirrhosis and hepatocellular carcinoma. Untreated, about 15% of patients with hepatitis C will eventually develop cirrhosis. **Hx:** Usually manifests as chronic liver disease because the acute infection is usually asymptomatic. **Dx:** Because treatments are available to eradicate HCV infection, screening is recommended for high-risk groups such as patients born between 1945 and 1965 (who represent ~75% of patients with HCV) and those with a history of injection drug use, HIV infection, or blood product transfusion prior to 1992. Test patients with chronic liver disease for **anti-HCV antibody.** Because the virus may **spontaneously clear** in up to half of affected patients, diagnosis of chronic infection is a 2-step process that requires both a positive serologic test for the HCV antibody and a **confirmatory molecular test for the presence of circulating HCV RNA**. Patients with positive antibodies and **NEGATIVE** HCV RNA generally have either: * **Resolved infection:** A minority of patients (15%-40%) are able to spontaneously clear HCV infection; these individuals are not infectious, have no sequelae of disease, and do not require treatment. * **False-positive** HCV antibody test Once the diagnosis has been confirmed with dual testing, patients should undergo **further evaluation** to identify the HCV **genotype and the extent of liver fibrosis.** **Tx:** Previous treatments were based on pegylated interferon and ribavirin, the introduction of protease inhibitors effective against HCV (eg, boceprevir, simeprevir, telepravir) and direct-acting antiviral agents (eg, ledipasvir-sofosbuvir) has markedly changed HCV therapy. Antiviral therapy for HCV infection is associated with significant morbidity; therefore, which patients are candidates for antiviral therapy should be carefully considered. Females, patients under age 40, patients with minimal or no cirrhosis, and those infected with genotypes 2 and 3 are more likely to respond to treatment. All patients with chronic hepatitis C should receive 💉**vaccination against hepatitis A and B**, which can cause fulminant hepatic failure in patients with preexisting hepatitis C. **Cx:** Extrahepatic complications of hepatitis C, including: **Mixed cryoglobulinemia syndrome** (eg, palpable purpura, arthralgias, glomerulonephritis, low complement levels), **lichen planus**, and **porphyria cutanea tarda (PCT).**

Answer 43

Hallmark of ischemic hepatopathy is a rapid and significant increase in the transaminaseswith modest accompanying elevations in total bilirubin and alkaline phosphatase. **AST and ALT levels peak at 25 to 250 times the upper limit of normal and can reach \>10,000 U/L.** This reflects diffuse liver injury due to hypotension; as a result of the liver's dual blood supply, diffuse injury is more common than focal infarction. In patients who survive the underlying cause of their hypotension (eg, septic shock, heart failure), liver enzymes typically return to normal within 1-2 weeks.

Answer 44

Type I * Lymphoproliferative or hematologic (eg, multiple myeloma) * Asymptomatic * Hyperviscosity (eg, blurry vision), thrombosis (eg, Raynaud phenomenon) * Skin: Livedo reticularis, purpura * Complement levels: **Normal** Mixed (types II & III) * Chronic HCV, HIV * Systemic lupus erythematosus * **Systemic: Fatigue, arthralgias** * Renal: **Glomerulonephritis**, HTN * Pulmonary: Dyspnea, pleurisy * Skin: **Palpable purpura**, LCV * **Low C4** **Mixed cryoglobulinemia syndrome (MCS)** is caused by immune complex deposition in small- to medium-size blood vessels, leading to endothelial injury and end-organ damage. It commonly presents with fatigue; nonblanching, palpable purpura; arthralgias; renal disease (eg, hematuria, proteinuria, glomerulonephritis); and peripheral neuropathies. Renal involvement is variable, but the most common manifestation is **hypertension**. Liver involvement (eg, e**levated transaminases**) is common. Patients rarely may have central nervous system or pulmonary involvement. MCS is most commonly associated with chronic inflammatory conditions such as hepatitis C virus (HCV) infection and systemic lupus erythematosus. Consequently, every patient suspected of having MCS should be tested for HCV, hepatitis B virus, and HIV. HCV-associated MCS immune complexes are formed from HCV, anti-HCV IgG, IgM anti-IgG antibodies (rheumatoid factor), and complement. Diagnosis of MCS can be confirmed serologically (**serum cryoglobulins, low complement levels**) or with a **skin/renal biopsy**. Treatment involves addressing the underlying disease and can also include **plasmapheresis** and **immunosuppression** (eg, glucocorticoids, rituximab) for patients with rapidly progressive or life-threatening courses.

Answer 45

Porphyria cutanea tarda (PCT) presents with fragile, photosensitive skin that develops **vesicles and bullae** with trauma or sun exposure (eg, dorsa of the hands). Healed lesions typically scar and can form both hypo- and hyperpigmented areas. HCV is strongly associated with PCT, and all patients with PCT should be screened. **Dx:** Diagnosis of PCT is supported by increased plasma and urine porphyrins. Tx: involves either serial phlebotomy or hydroxychloroquine along with management of underlying causes (eg, HCV).

Answer 46

Diffuse liver injury due to hypotension; as a result of the liver's dual blood supply, diffuse injury is more common than focal infarction. **Dx:** Rapid and significant increase in the transaminases with modest accompanying elevations in total bilirubin and alkaline phosphatase. AST and ALT levels peak at 25 to 250 times the upper limit of normal and can reach \>10,000 U/L. In patients who survive the underlying cause of their hypotension (eg, septic shock, heart failure), liver enzymes typically return to normal within 1-2 weeks.

Answer 47

Peptic ulcer Disease

Answer 48

The two most common causes of peptic ulcer disease are infection with **H. pylori** and the use of **nonsteroidal anti-inflammatory drugs (NSAIDs).** **Hx:** Pain or distress centered in the upper abdomen; 😊**relieved by food 🍗 or antacids.** The classic symptoms of **duodenal ulcer** occur in the absence of a food buffer and can include **epigastric pain 2-5 hours after meals**, on an empty stomach, or at night. **Dx:** The initial diagnosis of H. pylori infection may be done by **endoscopic studies** (either histologic examination of biopsy tissue OR rapid urease testing) OR **non-endoscopic studies** (serum antibody tests, the **urea breath test**, or **stool examination for H. pylori antigens)**. Ulcerative lesions visualized with endoscopy; 7%–25% of epigastric pain. **Tx:** **Triple therapy** consisting of a **PPI (antisecretory therapy), amoxicillin, and clarithromycin (antibiotic eradication)** is the most commonly used initial treatment. **Fu:** Patients should undergo fecal Helicobacter pylori antigen testing to verify eradication of the infection. **Urea breath test** and fecal antigen testing are practical and noninvasive methods for detecting any residual H. pylori infection. **Cx: Perforating Peptic Ulcer** Postprandial abdominal pain, weight loss, abdominal bruit (chronic presentation); pain out of proportion to tenderness on palpation

Answer 49

A perforated viscus typically presents with severe abdominal pain, fever, tachycardia, and signs of peritonitis (eg, rigidity, reduced bowel sounds, rebound tenderness). **Full-thickness erosion of a peptic ulcer** through the stomach or duodenal wall releases both air and caustic (ie, pH ~1-2) gastric secretions/contents into the peritoneal cavity. This quickly results in **chemical peritonitis** (eg, marked abdominal tenderness with guarding) and an early systemic inflammatory response (eg, fever, tachycardia) that can progress to sepsis and shock if left untreated. Patients with free perforation causing gross spillage of gastrointestinal contents (vs microperforation with little to no spillage) can often note the precise time the perforation occurred. Sudden, severe pain is typical. The diagnosis of gastrointestinal perforation is confirmed with **upright x-ray of the chest and abdomen**, which typically shows f**ree intraperitoneal air under the diaphragm (pneumoperitoneum).** Demonstration of intraperitoneal **free air** (eg, on upright x-ray) confirms the diagnosis and should prompt immediate **surgical consultation**, since many patients require surgical intervention and delay increases mortality (which is up to 30%, even with treatment).

Answer 50

Presentation * Rapid onset of periumbilical pain (often severe) * Pain **out of proportion** to examination findings * Hematochezia (late complication) Risk factors * **Atherosclerosis** (acute or chronic) * Embolic source (thrombus, vegetations) * Hypercoagulable disorders Cardiac embolic events in the setting of atrial fibrillation, valvular disease, or cardiovascular aneurysms; Acute thrombosis due to peripheral arterial disease or low cardiac output states Laboratory findings * Leukocytosis * Elevated amylase & phosphate levels * **Metabolic acidosis** (elevated **lactate**) Diagnosis * **CT** (preferred) or MR angiography * Mesenteric angiography if diagnosis is unclear Elderly patients with **vascular disease.** Intermittent mesenteric ischemia occurs from atherosclerotic obstruction of visceral arteries. CMI commonly presents with crampy, **postprandial epigastric pain (intestinal angina)**, food aversion, and weight loss. The pathophysiology of the pain is most likely related to shunting of blood away from the small intestine to meet the increased demand of the stomach. **Classic triad**: postprandial abdominal pain, weight loss, and abdominal bruit. **Px:** Acute mesenteric ischemia is characterized by **pain out of proportion to examination findings** and metabolic acidosis. Physical examination may show signs of malnutrition and may reveal an abdominal bruit in ~50% of patients, but can be otherwise unremarkable. **Dx:** Although abdominal x-ray and CT scans may demonstrate calcified vessels, diagnosis requires better visualization of the vessels. **CT angiography** is the preferred choice, although Doppler ultrasonography may also be helpful. Possible anion gap metabolic acidosis; 💀**abdominal plain films** may show classic **thumbprinting sign** (acute presentation). **Tx:** Treatment involves risk reduction (eg, tobacco cessation), nutritional support, and revascularization.

Answer 51

CMI commonly presents with crampy, **postprandial epigastric pain (intestinal angina), food aversion, and weight loss.** Patients may also report nausea, early satiety, and diarrhea. The anginal **pain frequently starts within the first hour of eating** and slowly resolves over the next 2 hours. The pathophysiology of the pain is most likely related to **shunting of blood away from the small intestine to meet the increased demand of the stomach.** In patients with atherosclerosis, the celiac or the superior mesenteric arteries may be narrowed and unable to dilate appropriately to maintain adequate blood flow to the intestines. **Px:** Physical examination may show signs of malnutrition and may reveal an abdominal bruit in ~50% of patients, but can be otherwise **unremarkable**. Although abdominal x-ray and CT scans may demonstrate calcified vessels, diagnosis requires better visualization of the vessels. **Dx: CT angiography** is the preferred choice, although Doppler ultrasonography may also be helpful. Treatment involves risk reduction (eg, tobacco cessation), nutritional support, and revascularization.

Answer 52

ZES is usually sporadic but is found in conjunction with multiple endocrine neoplasia type 1 (MEN-1) in 20% of cases. Gastrinomas usually occur in patients age 20-50 with dyspepsia, reflux symptoms, abdominal pain, weight loss, diarrhea, or frank gastrointestinal bleeding. **Dx:** Endoscopy often shows thickened gastric folds, multiple peptic ulcers, refractory ulcers despite proton pump inhibitor (PPI) use, or ulcers distal to the duodenum in the jejunum (suggesting excess gastric acid that cannot be fully neutralized in the duodenum). **Dx: Fasting serum gastrin level** (off PPI therapy for 1 week) should be checked in suspected gastrinoma; a level \<110 pg/mL rules it out, and a level **\>1000 pg/mL is diagnostic**. If gastrin is elevated, gastric pH should also be measured as gastrin may also be elevated due to failure of gastric acid secretion (achlorhydria). A gastrin level of 110-1000 pg/mL is non-diagnostic and requires a follow-up **secretin stimulation test**. Secretin stimulates the release of gastrin by gastrinoma cells. Normal gastric G cells are inhibited by secretin; therefore, secretin administration should not cause a rise in serum gastrin concentrations in patients with other causes of hypergastrinemia.

Answer 53

Extranodal marginal zone B cell lymphomas (low-grade B cell lymphoma of mucosa-associated lymphoid tissue [MALT]) of the stomach. It is present in 90% of patients with tumors. Chronic inflammation from **H pylori infection** results in stimulation of large numbers of antigen-dependent B and T cells in the gastric lamina. The chronic activation and proliferation eventually results in a monoclonal population of B cells that no longer depends on normal stimulatory pathways for growth. As a result, all patients with MALT lymphomas should be tested for H pylori infection, and patients with a positive result who have early-stage MALT lymphoma should undergo H pylori eradication therapy (eg, quadruple therapy). The majority of patients achieve complete remission with antibiotic treatment. Patients with more advanced malignancies or with H pylori-negative tumors should be considered for radiation therapy, immunotherapy (eg, rituximab), or single-agent chemotherapy.

Answer 54

**Acute appendicitis!** **Ectopic pregnancy, ovarian cyst or torsion** **Pelvic inflammatory disease** **Nephrolithiasis** **Pyelonephritis** **Others: And same as LLQ; also mesenteric lymphadenitis, cecal diverticulitis, Meckel’s diverticulum, intussusception**

Answer 55

Midepigastric pain radiating to RLQ; anorexia and nausea frequently present. **Ultrasonography** and CT may confirm diagnosis. 🥇 **Abdominal CT** is readily available in most emergency departments and is highly accurate (95%). Classic chronologic order: 1. Periumbilical pain (intermittent and crampy) 2. Nausea/vomiting 3. Anorexia 4. Pain migrates to RLQ (constant and intense pain), usually in 24 hours Studies estimate that there is a 10% to 20% reduction in the perceived intensity of the pain per decade after the age of 60. Only 22% of elderly patients with appendicitis present with classic symptoms, making the diagnosis more difficult.

Answer 56

RLQ or LLQ abdominal pain, nausea, fever; leukocytosis; suspect in women with unilateral pain

Answer 57

May be RLQ or LLQ; fever; abdominal tenderness, uterine or adnexal tenderness, cervical motion tenderness; cervical discharge

Answer 58

Right or left flank pain that may radiate to groin; hematuria

Answer 59

Fever, dysuria, and pain in right or left flank that may radiate to lower quadrant; urinalysis shows leukocytes and leukocyte casts

Answer 60

**Acute Diverticulitis** **Toxic megacolon** **Others: sigmoid volvulus, perforated colon, colon cancer, urinary tract infection, small bowel obstruction, inflammatory bowel disease, nephrolithiasis, pyelonephritis, fluid accumulation from aneurysm or perforation, referred hip pain, gynecologic causes, appendicitis (rare)**

Answer 61

**Diverticulosis** is characterized by herniation of the colonic mucosa/submucosa through the circular and longitudinal muscle layer due to elevated intraluminal pressure. Risk increases with age and is greatest in those with obesity, poor diet (eg, low dietary fiber, high red meat), and tobacco use. Although diverticulosis is usually asymptomatic, approximately 5%-15% of patients develop diverticular bleeding or diverticulitis.\ Obstruction of a diverticulum can result in a microscopic perforation contained by the mesentery, or frank perforation and development of a **peridiverticular abscess.** **Diverticulitis** results from obstruction at a diverticulum neck by fecal matter, leading to mucus production and bacterial overgrowth. Diverticulitis is classically associated with abdominal pain and fever. The pain is typically located in the left lower quadrant because the **sigmoid** is the most common region of the colon to be affected by diverticulosis. elevated luminal pressure or inspissated food particles cause erosion of the diverticular wall, leading to micro- or macroperforation and subsequent colonic wall inflammation. Most cases arise in the sigmoid colon (the site of the greatest intraluminal pressure) and present with the following: * **Left lower quadrant abdominal pain** * Nausea and **vomiting** * **Bladder symptoms** (eg, urgency, frequency, dysuria) or sterile pyuria (eg, positive leukocyte esterase, negative nitrite/bacteria) due to bladder irritation from adjacent sigmoid colon inflammation * Alteration in bowel habits (eg, constipation, diarrhea) A minority of patients (\<20%) develop rebound tenderness/guarding or a tender left lower quadrant mass. Diagnosis is usually made with imaging (eg, CT scan of the abdomen); antibiotic therapy is generally curative, but complications (eg, abscess, bowel obstruction, frank perforation, fistula) can occur and usually necessitate further therapy. **Hx:** Pain usually in LLQ but can be RLQ if ascending colon is involved; Other symptoms may include nausea, vomiting, and anorexia; **fever**. **Dx:** **CT** can diagnose complicated diverticular disease with abscess formation. More than 50% of patients with diverticulitis have **leukocytosis**. ❌Colonoscopy should be avoided in the acute setting because air insufflation may increase the risk for perforation. **Tx:** Oral antibiotic therapy with agents that are effective against anaerobes and gram-negative rods (**metronidazole and ciprofloxacin**) is a reasonable option for initial therapy in immunocompetent patients with isolated, uncomplicated acute diverticulitis who are able to tolerate oral intake. **Cx: Colovesical fistula** (connection between the colon and bladder). The mechanism is usually due to direct extension of a ruptured diverticulum or erosion of a diverticular abscess into the bladder. Patients typically develop **fecaluria (stool in the urine)** or **pneumaturia (air in the urine)** that usually occurs at the end of urination as the gas collects at the top of the bladder. Patients can also develop **recurrent urinary tract infections** (sometimes due to mixed flora with coliform organisms) or other nonspecific symptoms that can sometimes delay the diagnosis. Colovesical fistula can also occur in patients with Crohn disease or malignancy (usually of the colon). Abdominal CT scan with oral or rectal (not intravenous) contrast can confirm the diagnosis by showing contrast material in the bladder with thickened colonic and vesicular walls. Colonoscopy is usually recommended in patients diagnosed with colovesical fistula to exclude colonic malignancy. Treatment is typically surgical after resolution of the infection.

Answer 62

**Nonobstructive dilatation** of transverse and descending colon; systemic toxicity; associated with inflammatory bowel disease **(UC)** and Clostridium difficile infection. Acute worsening with **fever**, abdominal distension, leukocytosis, hypotension, and tachycardia. Other manifestations of toxic megacolon include altered mental status, **peritonitis**, and electrolyte abnormalities. If due to severe colitis with massive colonic distension, toxic megacolon may be the first presentation of IBD and is potentially lethal. Key to the diagnosis of toxic megacolon is radiologic evidence of colonic distension (eg, **\>6 cm dilation of right colon**) **with manifestations of severe systemic toxicity.** Consequently, the initial test of choice in suspected cases is abdominal x-ray, a noninvasive study that can be performed quickly, confirm the diagnosis, and exclude perforation. Conservative management (successful in \>50% of cases) can initially be instituted and includes **bowel rest, nasogastric suction**, and either corticosteroids with broad spectrum-antibiotics (due to IBD) or antibiotics targeted at Clostridium difficile.

Answer 63

A disorder of bowel motility leading to acute colonic dilatation in the absence of a obstructing lesion, often occurs due to severe illness, abdominal surgery, or medication. Etiologies * Major surgery, traumatic injury, severe infection * **Electrolyte derangement** (↓ K, ↓ Mg, ↓ Ca) * Medications (eg, opiates, anticholinergics) * Neurologic disorders (eg, dementia, stroke) Clinical findings * Abdominal distension, pain, obstipation, vomiting * Tympanic to percussion, ↓ bowel sounds * If perforation: guarding, rigidity, rebound tenderness Imaging * X-ray: **colonic dilation**, normal haustra, nondilated small bowel * CT scan: colonic dilation without anatomic obstruction Management * **NPO, nasogastric/rectal tube decompression** * Neostigmine if no improvement within 48 hr **Hx: Diuretic use and recent diarrhea** (due to foodborne gastroenteritis) can cause an electrolyte imbalance (eg, hypokalemia, hypomagnesemia), which can precipitate Ogilvie syndrome. The disorder may largely result from autonomic disruption of the colon. Accordingly, other common causes include severe trauma, severe infection, or major surgery (increased sympathetic drive relative to parasympathetic); neurologic disorders (eg, dementia, stroke, multiple sclerosis, Parkinson disease); and certain medications (eg, anticholinergics). Patients typically have severe abdominal **distension**, pain, vomiting, and obstipation (inability to pass stool or gas). The abdomen is often tympanic and exhibits hypoactive bowel sounds on auscultation. Abdominal plain films reveal colonic dilation (usually predominantly affecting the proximal colon) with normal haustral markings and a nondilated small bowel. CT scan provides diagnostic confirmation showing **colonic dilation with no anatomic obstruction**. Management involves bowel rest (NPO) and placement of nasogastric and rectal tubes for colonic decompression. Neostigmine can be given intravenously if symptoms fail to improve after 48 hours or if the cecal diameter on imaging exceeds 12 cm (which is a strong predictor of impending perforation).

Answer 64

Gastric and duodenal ulcers Variceal bleeding Mallory-Weiss tear Esophagitis Gastritis or gastroduodenal erosions Esophageal or gastric cancer Studies: CBC, PTT, INR, CMP. **EGD** (upper endoscopy), Melena - 14 hours Obscure: Cameron erosion - Large hiatal hernia NSAID ulcerations - Medication review Dieulafoy lesion - intermittend karge volume Crohn disease - manifestations Gastric antral vascular ectasia - female; autoimmune

Answer 65

Dyspepsia, Helicobacter pylori infection, NSAID use, anticoagulation, severe medical illness. Duodenal ulcer is more common in men than women, but **H pylori** is present in 70% of patients (men and women) who have a duodenal ulcer NOT associated with NSAID ingestion. The pain of gastric ulcers is often worse after eating due to increased acid secretion. DU is often worse on an **empty stomach** (possibly due to unopposed gastric acid emptying into the duodenum) and improves with food (due to alkaline fluid secretion into the duodenum). **Dx:** PPI before EGD Management of DU due to H pylori requires the following: * **Antisecretory therapy**, preferably a proton pump inhibitor (PPI) (eg, omeprazole, pantoprazole), and * **Antibiotic eradication** (eg, amoxicillin plus clarithromycin)

Answer 66

Stigmata of chronic liver disease on examination and evidence of portal hypertension or risk factor for cirrhosis (heavy alcohol use, viral hepatitis). Tx: Endoscopic Band Ligation; octreotide

Answer 67

Etiology * Sudden increase in abdominal pressure (eg, forceful retching) * **Mucosal** tear in esophagus or stomach (submucosal arterial or venous plexus bleeding) * Risk factors: Hiatal hernia, alcoholism Clinical presentation * Vomiting, **retching** * Hematemesis * Epigastric pain Diagnosis * Longitudinal laceration on endoscopy Treatment * **Most heal spontaneously** within 24 to 48 hours with supportive therapy. * If there is ongoing bleeding, IV vasopressin or injection of a sclerotic agent via endoscopy may be required Mallory-Weiss tear (MWT) is characterized by longitudinal tears in the mucosa near the **gastroesophageal junction**, with bleeding due to injury to the submucosal arteries or veins. It typically occurs due to a sudden increase in intraabdominal pressure (eg, retching, blunt abdominal trauma). MWT is a common cause of upper gastrointestinal (GI) hemorrhage and is often seen in association with alcohol abuse and hiatal hernia. The diagnosis can be confirmed on endoscopy. Bleeding stops spontaneously in 90% of patients. Those with ongoing bleeding can be treated endoscopically with electrocoagulation or local injection of epinephrine.

Answer 68

Forceful retching may increase intraesophageal pressure enough to cause a full-thickness effort rupture of the esophagus (Boerhaave syndrome), which may allow efflux of esophageal fluid and air into the mediastinum. The leaked gastrointestinal contents cause severe chest/abdominal painand a systemic inflammatory response (eg, fever, tachycardia) that can quickly progress to septic shock and death; the leaked air (pneumomediastinum) may be palpated as **suprasternal crepitus (subcutaneous emphysema).**

Answer 69

Heartburn, regurgitation, dysphagia; usually small-volume or occult bleeding

Answer 70

NSAID use, heavy alcohol use, severe medical illness; usually small-volume or occult bleeding

Answer 71

Progressive dysphagia, weight loss, early satiety, abdominal pain; usually small-volume or occult bleeding

Answer 72

ZD is most common in 👴🏾**elderly patients**, particularly men. It occurs in the posterior lower cervical esophagus near the cricopharyngeus muscle. Patients may complain of dysphagia and regurgitation. They often have foul-smelling breath (halitosis) secondary to pooling of material in the diverticulum. If particularly large, the diverticula may be palpable. Patients with ZD are at risk for aspiration pneumonia. ZD develops immediately above the upper esophageal sphincter with **posterior herniation** between the fibers of the cricopharyngeal muscle. Upper esophageal **sphincter dysfunction** and **esophageal dysmotility (motor dysfunction)** are believed to cause ZD. A **contrast esophagram**, which will clearly show the diverticulum, is the diagnostic test of choice. Oral contrast administration in patients with a history of aspiration is associated with a risk of pneumonitis. However, the risk can be reduced by a number of positioning techniques and is indicated to diagnose ZD unless the patient has severe swallowing difficulty. Moreover, other options to visualize the esophagus, including endoscopy, are associated with very serious risks of complications such as esophageal perforation. ZD is usually repaired surgically.

Answer 73

Erosion of the proximal end of a woven aortic graft into the distal duodenum or proximal jejunum can occur many years after surgery for abdominal aortic aneurysm. Often, the patient will have a smaller herald bleed, which is then followed by catastrophic bleeding. A high index of suspicion is necessary, as timely surgery can be lifesaving.

Answer 74

Diverticula Angiectasias or angiodysplasia Colonic polyp Colon cancer Ischemic colitis Acute small bowel (mesenteric) ischemia Hemorrhoids Infectious colitis Inflammatory bowel disease Meckel diverticulum Dx: Colonoscopy Alternative: technetium 99m pertechnetate–labeled red blood cell scan or angiography; enteroscopy Obscure: Angiectasias - Intermittent, usually occult bleeding; may also occur in colon Peutz-Jeghers syndrome - Perioral pigmentation, obstructive symptoms Meckel diverticulum - Possible abdominal pain Hemangioma - Possible cutaneous hemangiomas Malignancy - Weight loss, abdominal pain Hereditary hemorrhagic telangiectasia - Facial telangiectasias

Answer 75

Bleeding is arterial, resulting from medial thinning of the vasa recta as they drape over the dome of the diverticulum. Generally, patients do not have other symptoms. Painless, self-limited hematochezia. **Px:** Usually unremarkable unless large blood loss results in tachycardia, hypotension, and orthostasis. **Dx: Colonoscopy** may identify the bleeding diverticulum and permit endoscopic treatment with epinephrine and/or electrocautery; colonoscopy may also help identify other causes of bleeding such as vascular ectasias. **Tx:** endoscopic electrocautery

Answer 76

Angiodysplasia is characterized by dilated submucosal veins and arteriovenous malformations, and has an increased incidence after age 60. Account for up to 11% of episodes of lower gastrointestinal bleeding. They are painless dilated submucosal vessels that radiate from a central feeding vessel. Angiectasia is the most common cause of small intestinal bleeding in the elderly, accounting for up to 80% of cases. **Hx:** Chronic blood loss or acute **painless hematochezia** in elderly individual; frequently involves upper GI tract in addition to colon. Angiodysplasia is more frequently diagnosed in patients with advanced renal disease and von Willebrand (vW) disease, possibly due to the bleeding tendency associated with these disorders. Angiodysplasia may also be more common in patients with aortic stenosis (AS), possibly due to acquired vW factor deficiency (from disruption of the vW multimers as they traverse the turbulent valve space induced by AS). **Dx:** Patients may present with **iron deficiency anemia** and occult gastrointestinal bleeding or with hematochezia that is indistinguishable from diverticular hemorrhage. **Tx:** Cautery

Answer 77

**Hx:** Change in bowel habits, diarrhea, constipation, a feeling that the bowel does not empty completely, bright red blood in the stool, melanotic stools, and stools that are narrower in caliber than usual. Other signs include general abdominal discomfort (frequent gas pains, bloating, fullness, cramping), unintentional weight loss, fatigue, and vomiting. Findings of iron deficiency anemia in persons aged \>40 years require careful evaluation for colorectal cancer. **Dx:** **Guaiac fecal occult blood test (gFOBT)** uses a reagent that changes color in the presence of peroxidase, which is found in human blood, animal blood, and other dietary sources. Proper test performance typically requires the collection of two samples from three consecutive stools (six samples total). Approximately 3%-5% of persons with a positive FOBT will have colorectal cancer; up to 50% will have polyps. **Colonoscopy** is performed when colorectal cancer is suspected. Screening for patients with a first-degree relative with colorectal neoplasia (advanced adenoma characterized by size 1 cm or greater or high-grade dysplasia, or villous elements) at age younger than 60 years or two or more first-degree relatives with colorectal cancer diagnosed at any age. For these individuals, **colonoscopy screening should begin at age 40** years **or age 10 years before youngest age** at colorectal neoplasia or colorectal cancer diagnosis in the family, whichever is younger. **Tx:** **Stage I or stage II:** tumor **resection** is performed for cure. **Stage III:** the cancer is **resected**, and **adjuvant chemotherapy** is initiated. **Metastatic (stage IV):** removal of the primary tumor is indicated for palliative relief of obstruction or to stop bleeding. Isolated hepatic metastases can be **resected**, depending on the patient's overall functional status. **Rx:** First-line agents for stage III colorectal cancer include **5-fluorouracil** and **leucovorin** for 6 months; oral **capecitabine** for 24 weeks; or 5-fluorouracil, leucovorin, and oxaliplatin for 24 weeks.

Answer 78

Grossly visible protrusions from the flat mucosal surface of the intestine. They can be categorized as **neoplastic** (having malignant potential) and **non-neoplastic**. **Adenomas** (adenomatous polyps) are considered neoplastic polyps; findings that suggest a greater risk of malignant transformation (usually warranting more aggressive colonoscopic surveillance) include: Predominance of **villous features** (long glands on histologic examination), particularly in the presence of high-grade dysplasia Large size (eg, \>1 cm) High number (eg, \>3 concurrent adenomas) In addition, **sessile** (nonpedunculated) adenomatous polyps are associated with an increased risk of synchronous advanced neoplasia and often require careful follow-up to ensure complete removal. **Non-neoplastic polyps**, including hyperplastic polyps (arising from hyperplastic mucosal proliferation), hamartomatous polyps (eg, juvenile polyps, Peutz-Jeghers polyps), inflammatory pseudopolyps, and submucosal polyps (eg, lipomas, lymphoid aggregates), have **low malignant potential** and generally do not require enhanced surveillance.

Answer 79

Risk factors for atherosclerosis and evidence of vascular disease in elderly individual; abdominal pain. Tx: IV fluids; pain control; angiography, laprotomy

Answer 80

Severe abdominal pain out of proportion to physical findings; atherosclerotic or embolic risk factors; anion gap metabolic acidosis; bleeding a late finding

Answer 81

Bloody diarrhea, fever, urgency, tenesmus; exposure history

Answer 82

Tenesmus, diarrhea, hematochezia; history of receptive anal intercourse; positive bacterial or viral cultures (Neisseria, Chlamydia, or Treponema spp.; HSV)

Answer 83

Is due to **occlusion of an anal 👾crypt gland**, which allows for bacterial infection. Abscesses can form relatively acutely following gland obstruction due to the high levels of bacteria in the area. Risk factors for abscess development include **anoreceptive intercourse** and constipation, among others. Initially, a perianal abscess may cause pain only with defecation and mild pruritus, but as the infection progresses, the pain becomes constant and can be associated with systemic manifestations such as fever. Drainage may not be apparent unless a fistula forms. **Cx:** Untreated perianal abscesses often progress to form **anorectal fistulae, communications between the abscess and perirectal skin or nearby organs**. Early recognition followed by incision and drainage is essential to avoid such progression.

Answer 84

Causes * **Perianal abscess** * Crohn disease * Malignancy, radiation proctitis * Infection (eg, lymphogranuloma venereum) Clinical manifestations * Perirectal pain, **discharge** * Inflammatory papule/pustule * Palpable fistula tract Management * Assess extent of fistula * Gentle probe * Imaging (endosonography, fistulogram, MRI) * **Surgery** (eg, fistulotomy) Anorectal fistulas are most often due to rupture of a perianal abscess with formation of a residual sinus tract. They may also occur as a complication of Crohn disease, radiation proctitis, atypical infections (eg, lymphogranuloma venereum), or trauma. Examination of an anorectal fistula often reveals an external terminus and an indurated tract leading to the rectum. An internal terminus can sometimes be identified on anoscopy or by cautiously passing a probe through the fistula from the external opening. The diagnosis is often apparent on clinical grounds, but endoscopic sonography, MRI, or fistulogram can be used in complex cases to assess the extent of fistula formation. Management of an anorectal fistula requires **surgical intervention (eg, fistulotomy).** Fistulas can often be assessed more fully (eg, exploration with a soft probe) while patients are under anesthesia at the time of surgery to delineate the extent of the fistula. The entirety of the fistula must be addressed because residual fistula tracts can lead to persistent symptoms and fecal incontinence.

Answer 85

Hemorrhoids are the most common cause of low-volume rectal bleeding, especially in patients who do not have red-flag features (eg, passage of dark blood or blood mixed with stool, fever, abdominal pain, change in bowel habits) to suggest more serious causes. **Hx:** Intermittent mild rectal bleeding associated with **straining** on bowel movement. Streaks of bright red blood on the toilet paper or on the outside of a firm stool. **Dx:** Digital rectal exam; anoscopy Dietary factors * Increased fluid intake * **Increased fiber intake** (foods, fiber supplements) * Reduced fat intake * Moderation of alcohol intake Behavioral factors * Limit time sitting on toilet (eg, 3 minutes) * Limit defecation to once daily * Avoid straining during defecation Topical agents * Analgesics (eg, benzocaine) * Astringents (eg, witch hazel) * **Hydrocortisone anusol cream** The diagnosis is usually obvious based on clinical findings. **Anoscopy** is useful for those whose hemorrhoids are not palpable on examination, but further diagnostic testing is not usually required for young, otherwise healthy patients with typical symptoms. Initial management of uncomplicated hemorrhoids includes increased intake of **fluid and fiber** (eg, psyllium husk), **reduction in fat and alcohol intake, and regular exercise**. Additional measures may include phlebotonics (eg, calcium dobesilate), topical hydrocortisone, astringents (eg, witch hazel), and local anesthetics (eg, benzocaine, lidocaine). More aggressive management, including rubber band ligation and surgical hemorrhoidectomy, is generally advised only for patients with refractory symptoms or prolapsed hemorrhoids that cannot be reduced manually (ie, grade IV hemorrhoids). When they thrombose, they are associated with acute pain and are hard and nodular on physical examination. **Tx:** Internal: Rubber Band Ligation; External; Excision.

Answer 86

An anal fissure is a split in the anoderm of the anal canal. It generally occurs after the passage of a hard bowel movement. **Dx:** Patients present with **excruciating pain on defecation** with blood found on the toilet paper. After the bowel movement, the patient may complain of an ache or spasm that resolves after a couple of hours. **Tx:** Anal sphincter relaxation; **🧨nitroglycerein; nifedipine.**

Answer 87

External hemorrhoid * Dusky/**purple** lump or polyp * Itching, bleeding * Thrombosis: acute enlargement with pain Internal hemorrhoid * Itching, painless bleeding, leakage of stool * Detected with digital rectal exam or anoscopy Perianal abscess * Gradual onset * **Fluctuant mass**/swelling with erythema * Fever Anogenital wart * Chronic onset * Soft papules, plaques, or cauliflower-shaped masses * Mild itching, bleeding Anorectal cancer * Squamous cell carcinoma most common * Bleeding, pain * Ulcerating, enlarging mass

Answer 88

Diarrhea is defined as more than three loose stools per day. Diarrhea can be divided into 3 main categories: **watery, fatty, and inflammatory.** **Watery diarrhea** can be further broken down into **osmotic, secretory, and functional**. **Secretory diarrhea** include larger daily stool volumes (\>1 L/day) and diarrhea that occurs even during fasting or sleep. Secretory diarrhea most commonly occurs when luminal ion channels are disrupted in the gastrointestinal tract, resulting in a state of active secretion. Many patients confuse true diarrhea with three other conditions: pseudodiarrhea (the frequent passage of small volumes of stool), fecal incontinence, and overflow diarrhea caused by fecal impaction. Acute diarrhea is present for less than 14 days, persistent diarrhea has been present for at least 14 days but 4 weeks or less, and diarrhea is considered to be chronic if it has been present for more than 4 weeks. Although the vast majority of episodes of acute diarrhea are caused by viruses and are self-limited, further clinical evaluation is indicated in those who have bloody stools, body temperature greater than 38.5°C (\>101.3°F), significant abdominal pain, severe diarrhea causing symptomatic dehydration, recent antibiotic use, a history of inflammatory bowel disease, or immunocompromised states; food handlers; the elderly; or pregnant women. Because most episodes of diarrhea are self-limited, diagnostic testing generally is reserved for patients with severe diarrheal illness characterized by fever, blood in the stool, or signs of dehydration (weakness, thirst, decreased urine output, orthostasis) or patients with diarrhea lasting \>7 days.

Answer 89

**Medications** **Carbohydrate intolerance** **Irritable bowel syndrome (diarrhea predominant)** **Inflammatory bowel disease (ulcerative colitis, Crohn disease)** **Microscopic colitis** **Celiac disease** **Pancreatic insufficiency** **Enteral feedings** **Dumping syndrome** **Small bowel bacterial overgrowth** **Bile acid malabsorption** **Bile acid deficiency** **Radiation exposure** **Whipple disease** **Common variable immune deficiency** **Factitious diarrhea**

Answer 90

Presence of poorly absorbed solutes in the lumen of the gut. **Hx:** Lactose or fructose intake, use of artificial sweeteners (sorbitol, mannitol), bloating, excess flatus. **Dx:** **Qualitative fecal fat (Sudan stain):** Sensitivity \>90% for significant steatorrhea **Quantitative fecal fat (48- or 72-h collection):** Values \>10 g/24 h indicate fat malabsorption A fecal fat study is usually indicated for evaluating a patient with noninvasive diarrhea. However, test results are valid only if the patient ingests an adequate amount of dietary fat (\>100 g/d). Any cause of diarrhea may mildly elevate fecal fat values (6–10 g/24 h), but values in excess of 10 g/24 h almost always indicate primary fat malabsorption. **Stool electrolytes** (sodium, potassium): **Osmotic gap** (290 – [2 × (stool Na+ + stool K+)]); **An increased gap greater \> 100 mOsm/kg indicates an 🙌🏽_osmotic_ cause of diarrhea**. Lactose malabsorption is the most common cause of a stool osmotic gap. A decreased gap **\<50 mOsm/kg suggests _secretory_ diarrhea.** **Stool pH:** pH \<6.0 suggests carbohydrate malabsorption **Hydrogen breath test:** Lactose metabolized by bacterial flora in distal small intestine releases hydrogen, which is excreted by lungs **Tx:** Dietary exclusion

Answer 91

Acarbose, antibiotics, antineoplastic agents, magnesium-based antacids, metformin, misoprostol, NSAIDs, proton pump inhibitors, quinidine Withhold suspected medications

Answer 92

Clinical findings * Watery, nonbloody diarrhea; fecal urgency & incontinence * Abdominal pain, fatigue, weight loss, arthralgias Triggers * Smoking, medications (eg, NSAIDs, PPIs, SSRIs, ranitidine) Diagnosis * Colonoscopic biopsy with lymphocytic infiltration of lamina propria * Collagenous: thickened subepithelial collagen band * Lymphocytic: high levels of intraepithelial lymphocytes Management * Remove possible triggers * Antidiarrheal medications & budesonide Microscopic colitis (MC) is an immune-mediated colitis characterized by **watery**, nonbloody diarrhea. MC is a **secretory diarrhea** and, unlike osmotic diarrhea, may occur during periods of fasting and/or at **night🌃**. Other symptoms can include fecal urgency, incontinence, abdominal pain, fatigue, and weight loss. Blood and stool studies are usually unremarkable (eg, normal C-reactive protein and hemoglobin, negative fecal occult blood test). The diagnosis is confirmed with colonoscopy and biopsy; although the colon appears grossly normal, biopsy of the mucosa reveals a **mononuclear inflammatory infiltrate within the lamina propria.** The disease is divided histologically into 2 types: * **Collagenous colitis** - characterized by a **thickened subepithelial collagen band** * **Lymphocytic colitis** - characterized by **high levels of intraepithelial lymphocytes** MC is likely due to an abnormal immune response to various gastrointestinal and external agents. Certain medications—including nonsteroidal anti-inflammatory drugs (NSAIDs), proton pump inhibitors, and selective serotonin reuptake inhibitors—have been associated with the development of MC, as has smoking. Those with other autoimmune conditions (eg, celiac disease, autoimmune thyroiditis) are at increased risk. Older women (age \>60) are disproportionately affected. Initial management of MC includes smoking cessation and withdrawal of triggering medications. If diarrhea persists, budesonide and antidiarrheal medications (eg, loperamide) can be considered.

Answer 93

Psychiatric history, history of **laxative abuse**; diagnosis of exclusion; A patient's fixation on body image and weight loss may be a clue to laxative abuse. Nocturnal bowel movements and abdominal cramps are common accompanying symptoms. Low stool osmolality; stool magnesium \>90 meq/L may be diagnostic **Dx: Stool osmolarity: \<250 mOsm/kg** suggests factitious diarrhea; Diagnosis is supported by a positive stool screen for diphenolic (eg, bisacodyl) or polyethylene-containing laxatives. Diagnosis is further suggested by the characteristic colonoscopy finding of **melanosis coli,** which is **dark brown discoloration of the colon with pale patches of lymph follicles that can give the appearance of alligator skin.**

Answer 94

Intolerance to wheat products Celiac disease (gluten-sensitive enteropathy) is an immunologic response to dietary gliadins in patients who are genetically at risk as determined by the presence of HLA-DQ2 or HLA-DQ8. **Hx:** Classic symptoms include steatorrhea and weight loss, but many patients have only mild or nonspecific symptoms that often result in an erroneous diagnosis of IBS. Iron deficiency anemia is a common finding, as are associated autoimmune diseases such as Hashimoto thyroiditis and type 1 diabetes mellitus. Patients with celiac disease may have difficulty absorbing supplemental iron and levothyroxine **Dx:** **Anti Tissue transglutaminase antibody IgA (tTG IgA):** Sensitivity (69%–93%), specificity (96%–100%) Patients with a positive tTG IgA antibody assay should undergo upper endoscopy with **small bowel biopsy** showing intraepithelial lymphocytes, **crypt hyperplasia**, and partial to total **villous atrophy** (reduced mucosal surface area). **Extraintestinal Manifestations:** * Hematologic: Anemia (low iron, vitamin B12, folate), functional asplenia * Musculoskeletal: Osteopenia or osteoporosis, osteomalacia, arthropathy * Neurologic: Seizures, peripheral neuropathy, ataxia * Reproductive: Infertility, recurrent miscarriages * Skin: **Dermatitis herpetiformis** * Renal: Glomerular IgA deposition * Other: Enamel defects, abnormal liver chemistry tests, vitamin-deficient states **Tx:** Gluten-free diet.

Answer 95

Whipple's disease is a rare multi-systemic illness. It is an infectious disease caused by the 🦠**bacillus Tropheryma whippelii.** **Hx:** It is most commonly seen in white men in the fourth-to-sixth decades of life, and often presents with weight loss. Gastrointestinal symptoms include **abdominal pain, diarrhea, and malabsorption with distension, flatulence, and steatorrhea**. Extraintestinal manifestations include **migratory polyarthropathy, chronic cough, and myocardial or valvular involvement** leading to congestive failure or valvular regurgitation. Later stages of the disease may be characterized by dementia and other central nervous system findings, such as supranuclear ophthalmoplegia and myoclonus. Intermittent low-grade fever, **pigmentation** and lymphadenopathy may also be occasionally seen. **PAS positive** material in the lamina propria of the small intestine is a classical biopsy finding.

Answer 96

Malabsorption of fat from pancreatic or bile salt insufficiency (eg, chronic pancreatitis **Hx:** Steatorrhea, chronic pancreatitis, pancreatic resection, weight loss Tests for excess fecal fat, features of chronic pancreatitis on imaging (eg, pancreatic calcification on CT)

Answer 97

Greasy malodorous stools, increase in stool frequency, stools that are tenacious and difficult to flush, as well as changes in bowel habit according to the fat content of the diet. IgA antiendomysial antibodies and antibodies against tissue transglutaminase

Answer 98

Osmotic diarrhea Modify enteral feeding

Answer 99

Postprandial flushing, tachycardia History of gastrectomy or gastric bypass surgery

Answer 100

Excessive bacterial colonization of the small bowel lumen **Hx:** May manifest with bloating, diarrhea, and features of malabsorption. Intestinal dysmotility (eg, systemic sclerosis), bloating, excess flatus, malabsorption Duodenal aspirate for bacterial culture, response to empiric antibiotics, hydrogen breath testing A clue to the presence of bacterial overgrowth is finding a low serum vitamin B12 level (bacteria bind vitamin B12 and cleave it from intrinsic factor) and a high serum folate level (intestinal bacteria synthesize folate). **Hx:** Common conditions that predispose patients to bacterial overgrowth include diabetes, systemic sclerosis, and surgically created blind loops (ie, T Patients typically have mild abdominal pain, bloating, flatulence, and watery diarrhea. Vitamin B12 deficiency is common due to bacterial consumption; however, folate levels may be elevated due to bacterial production of the nutrient. The gold standard for diagnosis is a jejunal aspirationdemonstrating a high bacterial concentration (eg, \>103 colony-forming units/mL); however, this test is invasive and not easily performed. SIBO is more commonly diagnosed by a carbohydrate breath test using either glucose or lactulose. Patients with SIBO have an earlier peak in breath hydrogen/methane (due to carbohydrate metabolism by bacteria in the small intestine) compared to those without SIBO (in whom carbohydrate metabolism primarily occurs in the colon). Treatment is with **oral antibiotics (eg, rifaximin, neomycin)** to reduce bacterial load. **Tx:** Although the gold standard is aspiration of duodenal luminal contents for quantitative culture at the time of upper endoscopy, many clinicians first attempt a trial of empiric antibiotics to assess if the patient's symptoms improve. Having segments of small intestine excluded from the usual stream of gastric acid, bile, and proteolytic enzymes, which all act to decrease excess bacterial growth in the small intestine, is a risk factor for bacterial overgrowth. The diarrhea in bacterial overgrowth can be from deconjugation of bile salts from the intestinal bacteria, leading to fat malabsorption, as well as from decreased disaccharidase levels, leading to carbohydrate malabsorption. **Duodenal aspirate:** Quantitative bacterial culture; responds to empiric antibiotic trial Culture of the normally sterile small intestine or carbohydrate (lactulose, glucose, or d-xylose) breath testing can be done to substantiate the diagnosis; alternatively, in some patients an empiric trial of antibiotic therapy can be considered.

Answer 101

Resection of \<100 cm of terminal ileum Empiric response to cholestyramine

Answer 102

Cholestasis, resection of \>100 cm of terminal ileum Tests for excess fecal fat, response to medium-chain triglyceride diet

Answer 103

History of radiation therapy (may begin years after exposure) Bowel imaging, characteristic biopsy findings

Answer 104

Pulmonary disease, recurrent Giardia infection Immunoglobulin assay

Answer 105

In an immunocompromised patient, test for Mycobacterium avium complex (MAC) by sending stool for acid-fast bacillus stain and culture because disseminated MAC infections often involve the GI tract and cause diarrhea; also test for viruses (cytomegalovirus, adenovirus, herpes simplex virus) and protozoa (cryptosporidium, Isospora spp., microsporidia).

Answer 106

Patients with jaundice should be characterized as having unconjugated (indirect reacting) or conjugated (direct) hyperbilirubinemia. **Unconjugated hyperbilirubinemia:** **Hemolysis, ineffective erythropoiesis, or enzyme deficiencies (the commonest in adults being Gilbert syndrome).** **❗Conjugated hyperbilirubinemia:** Indicates significant liver dysfunction, either **hepatocellular or cholestatic (obstructive);****Hepatocellular damage** (viral or alcoholic hepatitis). **Cholestatic** disease of **bile ducts** or a cause of impaired bile excretion. Ultrasound or CT scan will evaluate the patient for an obstructing cancer or stone disease versus intrahepatic cholestasis.

Answer 107

If jaundice occurs in childhood and is associated with **unconjugated hyperbilirubinemia ddx includes:** * Hemolytic diseases (G6PD deficiency and spherocytosis), * Gilbert disease and Crigler-Najjar syndrome. If associated with **conjugated hyperbilirubinemia:** * **Viral hepatitis** is the most common cause. * Less common causes include **Wilson disease** and milder forms of **galactosemia.**

Answer 108

**Unconjugated hyperbilirubinemia:** * **Viral hepatitis** accounts for up to 75% of jaundice in patients **younger than 30**, but only accounts for 5% of jaundice in patients older than 60 years. * **Extrahepatic obstruction** (gall stones, strictures, and most importantly pancreatic cancer) accounts for more than 60% of jaundice in patients **older than 60 years**. * **Congestive heart failure** accounts for around 10% of jaundice in patients **older than 60,** * **Metastatic disease** accouns for around 13%. of jaundice in patients **older than 60,** * **Hemolytic anemia** **Dx:** When obstruction is suspected, ultrasound or CT scan is the appropriate initial test. If dilated bile ducts are seen, then ERCP or PTC should be done.

Answer 109

Megestrol Corticosteroids Cannabinoids J-Tube G-Tube PEG (artificial nutrition) **Cx:** edema, aspiration, peritonitis

Answer 110

Ingestion of preformed bacterial toxins results in nausea and vomiting followed by diarrhea within 12 hours. (Toxins are ingested, and no intestinal microbial growth is required; symptoms occurs rapidly, within 2–12 hours)

Answer 111

Potato salad, mayonnaise, ham 1–8 h

Answer 112

Fried rice 1–8 h

Answer 113

Beef, poultry 8–24 h

Answer 114

(Toxins produced by intestinal microbes that act directly on secretory mechanisms in the intestinal mucosa, causing watery diarrhea). Approximately one-third of travelers to underdeveloped countries will develop **travelers’ diarrhea.** Of those, 40% will alter their plans because of the symptoms, 20% will be bed-bound for at least 1 day, and 1% will require hospitalization. Most cases of travelers’ diarrhea are due to enterotoxigenic E coli. **Tx:** The antibiotic of choice for travelers’ diarrhea is a **fluoroquinolone** (ciprofloxacin, ofloxacin, or norfloxacin) with trimethoprim/sulfamethoxazole or azithromycin being acceptable alternatives.

Answer 115

Disruption of intestinal mucosal ion transport and subsequent water secretion (eg, cholera) **Hx:** Shellfish 8–72 h

Answer 116

**Hx:** Salads, cheese, meats 8–72 h **Tx:** Although prophylactic antibiotics are not recommended for traveler's diarrhea, empiric antibiotics (quinolones) may be appropriate for patients with symptoms. Untreated traveler's diarrhea usually resolves in 3 to 5 days, but treatment can improve symptoms and shorten the course.

Answer 117

(Infecting organisms adhere to the gastrointestinal mucosa and compete with normal bowel flora)

Answer 118

Travel history 1–8 d

Answer 119

Giardia duodenalis (sometimes noted as G lamblia or G intestinalis) is common in rural areas and developing countries, and has an incubation period of 1-2 weeks. It is most commonly transmitted by contaminated water but can be foodborne or transmitted person-to-person via a fecal-oral route. Most patients are **asymptomatic**; however, a significant minority of those who do develop clinical illness may go on to develop chronic giardiasis characterized by **malabsorption, weight loss, or persistent gastrointestinal distress.** **Dx:** The preferred confirmatory test for giardiasis is a **stool antigen assay** (direct immunofluorescence or ELISA). **Stool microscopy for oocysts and trophozoites** can also identify the organism and is useful in resource-poor settings or if other parasitic organisms are suspected. Some facilities also offer a nucleic acid amplification assay. **Tx: Metronidazole** is the preferred treatment. Asymptomatic carriers do not usually need treatment.

Answer 120

Acute or chronic watery diarrhea in an immunocompromised patient; outbreak in a nursing home or day care center or on a cruise ship 1–8 d

Answer 121

(Infecting organisms invade and destroy intestinal mucosa, resulting in bloody diarrhea) Minimal Inflammation

Answer 122

Minimal inflammation Outbreaks of diarrhea in families; on cruise ships and airplanes; and in day care centers, extended care facilities, or schools are commonly associated with norovirus. Acute diarrhea for 1–3 d For most patients, this finding represents a self-limited gastroenteritis. Features or clinical characteristics that require additional evaluation for acute diarrhea include fever; bloody stools; diarrhea in pregnant, elderly, or immunocompromised patients; hospitalization; employment as a food handler; recent antibiotic use; volume depletion; or significant abdominal pain.

Answer 123

Moderate Inflammation.

Answer 124

Infection with Salmonella usually occurs by ingesting contaminated **beef, poultry, eggs or dairy**, but has also been associated with handling **turtles**, **lizards**, and other **reptiles**. Salmonella gastroenteritis is often associated with fever and bloody diarrhea.

Answer 125

Poultry, raw milk, travel history Reactive arthritis can occur after Shigella, Salmonella, and Campylobacter infections. Guillain-Barré syndrome is associated with Campylobacter and Yersinia infections.

Answer 126

Travel history

Answer 127

Raw milk Severe inflammation

Answer 128

Routine stool culture cannot distinguish pathogenic E. coli from normal fecal flora. Therefore, in the setting of blood in the stool, test specifically for shiga toxin. If symptoms have persisted beyond 7 days, stool should be examined for ova and parasites. Travel history 12 h–8 d **Hemolytic uremic syndrome** (hemolytic anemia, thrombocytopenia, **acute kidney injury**) can occur with Shiga toxin–producing E. coli or Shigella infection.

Answer 129

Routine stool culture cannot distinguish pathogenic E. coli from normal fecal flora. Therefore, in the setting of blood in the stool, test specifically for E. coli O157:H7 If symptoms have persisted beyond 7 days, stool should be examined for ova and parasites.

Answer 130

(Toxins produced by intestinal organisms cause destruction of mucosal cells and associated inflammation, resulting in dysentery: bloody stools containing inflammatory cells)

Answer 131

C. difficile infection is an inflammatory condition of the colon caused by the ingestion of the spore-forming, anaerobic, gram-positive bacillus. The inflammatory response is secondary to toxin-induced cytokines (toxins A and B) in the colon. Findings can range from watery diarrhea to ileus and life-threatening conditions (toxic megacolon, perforation, sepsis). Disruption in the mucosal barrier secondary to infection or inflammation. **Hx:** Health care facility or antibiotic exposure; typically have **diarrhea up to 10 to 15 times daily**, lower abdominal pain, cramping, fever, and leukocytosis that often exceeds 15,000/µL (15 × 109/L) **Dx:** **C. difficile toxin enzyme immunoassay** should be performed if recent antibiotic use or hospitalization; sensitivity 70%–80% and specificity \>97% for toxins A and B. Fecal specimens collected after 3 days of hospitalization have a very low yield for standard bacterial pathogens, and routine stool culture is not indicated for inpatients with diarrhea unless there is evidence of a specific outbreak. Clostridium difficile **polymerase chain reaction (PCR)** and **stool culture** should be considered in patients with any features that require additional evaluation. **Sigmoidoscopy** of yellowish plaques (pseudomembranes) that cover the colonic mucosa or by detection of C difficile toxin in the stool. The pseudomembranes consist of a tenacious fibrinopurulent mucosal exudate that contains extruded leukocytes, mucin, and sloughed mucosa. Isolation of C difficile from stool cultures is nonspecific because of asymptomatic carriage, particularly in infants. **Tx:** **Oral vancomycin** and **IV metronidazole.** Recommended treatment of **severe disease** is **oral vancomycin** ❌**Antidiarrheal agents** should be avoided in patients with suspected inflammatory diarrhea (eg, diarrhea due to ulcerative colitis, C. difficile infection, or Shiga toxin–producing E. coli) because of the association with **toxic megacolon.**

Answer 132

Ground beef, raw vegetables 12–72 h

Answer 133

The Norwalk virus, reoviruses, and adenoviruses are common causes. Generally, these illnesses are self-limited, and will resolve within 5 days.

Answer 134

PTA, also known as **quinsy**, is an acute bacterial infection of the region between the tonsil and the pharyngeal muscles. It begins as persistent tonsillitis/pharyngitis and progresses to cellulitis/phlegmon, with pus collecting into an abscess within a week of symptom onset. PTA is most common in older adolescents and young adults, and drug or alcohol use increases the risk. Examination findings in PTA can include spasm of the jaw muscles (trismus) (which often limits the physical examination), muffled **"hot potato" voice**, and swelling of peritonsillar tissues with deviation of the uvula to the contralateral side. Treatment involves needle aspiration or incision and drainage plus antibiotic therapy to cover Group A hemolytic streptococci and respiratory anaerobes.

Answer 135

Sialadenosis is commonly found in patients with advanced liver disease (eg, alcoholic and nonalcoholic cirrhosis). It is also seen in patients with altered dietary patterns or malnutrition (eg, diabetes, bulimia). Sialadenosis is a benign, noninflammatory swelling of the salivary glands. It is associated with abnormal autonomic innervation of the glands, with accumulation of secretory granules in acinar cells. Differential diagnosis includes sialadenitis (focal tenderness, erythema, fever), salivary gland stones (glandular swelling and pain with meals), and malignancy. No management is needed other than to address any underlying nutritional disorders.

Answer 136

Caused by mechanical obstruction, leading to postprandial pain and vomiting with early satiety. Common causes of gastric outlet obstruction include gastric malignancy, peptic ulcer disease, Crohn disease, strictures (with pyloric stenosis) secondary to ingestion of caustic agents, and gastric bezoars. Acid ingestion causes fibrosis 6-12 weeks after the resolution of the acute injury. Physical examination can show an abdominal **succussion splash**, which is elicited by placing the stethoscope over the upper abdomen and rocking the patient back and forth at the hips. Retained gastric material \>3 hours after a meal will generate a splash sound and indicates the presence of a hollow viscus filled with both fluid and gas. Upper endoscopy is usually required to confirm the diagnosis, and treatment is primarily surgical.

Answer 137

Etiology * Anatomical abnormalities (eg, strictures, surgery) * Motility disorders (eg, diabetes mellitus, scleroderma) Signs/symptoms * Abdominal pain, diarrhea, bloating, flatulence * Malabsorption, weight loss, anemia, vitamin deficiency Diagnosis * Jejunal aspirate & culture showing \>105 organisms/mL * Carbohydrate breath testing (eg, lactulose, glucose) Organisms * Streptococci, Bacteroides, Escherichia, Lactobacillus Treatment * Antibiotics (eg, rifaximin, amoxicillin-clavulanate) * Avoid antimotility agents (eg, narcotics) * Dietary changes (eg, high-fat, low-carbohydrate) * Promotility agents (eg, metoclopramide) The proximal small intestine normally contains minimal bacterial colonization due to gastric acidity and peristalsis; however, **gastric bypass procedures** (Roux-en-Y gastric bypass) **result in a blind loop of intestine that allows for excessive bacterial growth**. Conditions that alter intestinal motility (eg, systemic sclerosis, diabetes mellitus), anatomy (eg, strictures), or gastric/pancreatic secretions (eg, atrophic gastritis, chronic pancreatitis) also predispose to SIBO. Patients with SIBO typically develop bloating, flatulence, abdominal discomfort, and watery diarrhea; in severe cases, malabsorption (eg, steatorrhea) and weight loss are seen. Laboratory studies are frequently normal but may demonstrate nutritional deficiencies (eg, vitamin B12, fat-soluble vitamins) and associated **macrocytic anemia**. Diagnostic tests include carbohydrate breath tests (eg, lactulose, glucose) that measure the production of hydrogen by intestinal flora. Endoscopy with jejunal aspirate and culture showing increased bacterial burden are also used. Management involves correction of the underlying abnormality, dietary modification, and a short course of empiric antibiotics (eg, rifaximin).

Answer 138

**Roux-en-Y gastric bypass** bypasses most of the stomach by creating a small gastric pouch, a gastrojejunal (GJ) anastomosis, and a jejunojejunal anastomosis. Weight loss results from restricting food consumption (smaller gastric pouch) and inducing malabsorption as nutrients can only be absorbed in the common limb (where food from the alimentary limb meets pancreatic enzymes/bile acids from the biliopancreatic limb). **Cx:** The procedure is associated with several postoperative complications. **Stomal (anastomotic) stenosis** is caused by progressive narrowing of the GJ anastomosis that leads to obstruction of gastric pouch outflow. This complication usually occurs within the first year after surgery, likely due to local tissue ischemia and ulceration. Patients typically have progressivesymptoms including nausea, postprandial vomiting, gastroesophageal reflux, and **dysphagia**, **to the point of not tolerating liquids.** Diagnosis requires visualization of the GJ anastomosis via **esophagogastroduodenoscopy (EGD),** during which balloon dilation can be performed to open the narrowing. Patients sometimes require surgical revision if balloon dilation fails.

Answer 139

Stress ulcerations are exceedingly common in patients requiring ICU-level care, and typically develop within hours to days of severe physiologic stress. Risk factors include shock, sepsis, coagulopathy, mechanical ventilation, traumatic spinal cord/brain injury, burns, and high-dose corticosteroids. The etiology is multifactorial and likely includes **splanchnic hypoperfusion,** reflux of bile salts, and accumulation of **uremic toxins** that impair formation of the protective mucosal layer around the stomach, allowing for mucosal injury and bleeding. Stress ulcers typically form in the proximal stomach and duodenum and may result in GI bleeding, which can be occult (eg, anemia, positive fecal occult blood testing) or clinically obvious (eg, melena, hematemesis) with shock. Prophylactic acid suppressive agents (eg, proton pump inhibitors [PPIs], H2 blockers) are a mainstay in the prevention of stress ulcerations. However, they are typically reserved for high-risk patients (eg, bleeding diathesis, prolonged mechanical ventilation, recent GI bleed) due to the potential harms associated with these agents, including pneumonia and Clostridiodes (formerly Clostridium) difficile infection. Patients who develop ulcerations should receive PPIs and close monitoring; endoscopy may be required in those with clinically significant bleeding.

Answer 140

Epidemiology Rule of 2s: * **2% prevalence** * Presentation often by **age 2** * **2:1** male/female ratio * Location within **2 feet of ileocecal valve** Clinical presentation * May be asymptomatic, incidental finding * Painless lower gastrointestinal bleeding * ± Anemia Complications * Intussusception * Volvulus * Intestinal obstruction Diagnosis * **Technetium-99m pertechnetate scan** Meckel diverticulum results from a partial remnant of the fetal vitelline duct, an embryologic structure that typically obliterates in the first trimester. A Meckel diverticulum may contain ectopic gastric mucosa (or, less commonly, pancreatic tissue), which secretes hydrochloric acid. Acidity can cause surrounding small-bowel ulceration and subsequent bleeding, which may lead to pallor and anemia if chronic. Stools can range in color from dark red or maroon to black depending on colonic transit time; the latter is more common in adults. Abdominal pain, diarrhea, and vomiting are uncommon. The best diagnostic test is a technetium-99m pertechnetate scan (Meckel scan), which shows increased uptake of technetium-99m by gastric mucosa and therefore identifies ectopic gastric tissue. This test is noninvasive, highly sensitive and specific, and emits little radiation. In symptomatic patients, surgical resection is necessary to prevent further bleeding or other complications (eg, intussusception, obstruction).

Answer 141

Finding a dilated, stool-filled anal canal with poor tone on the physical examination of a well-grown child supports the diagnosis of functional constipation. Hirschsprung disease is usually suspected in the chronically constipated child despite the vast majority of such children having functional constipation. The treatment of functional constipation, once it has been established as the diagnosis, emphasizes dietary changes and counseling of parents regarding proper toileting behavior. Effective stool softeners are available as a second line option. An extensive workup of this patient would likely be negative and expensive, and is not indicated. Hirschsprung usually presents in infancy with increasingly difficult defecation in the first few weeks of life. Typically no stool is found in the rectum, and anal sphincter tone is abnormal. Diagnosis of Hirschsprung disease may be made with rectal manometry and rectal biopsy.

Answer 142

Infantile hypertrophic pyloric stenosis is most common in first-born boys and typically begins at age 3-5 weeks with projectile, nonbilious vomiting after every feed. Classic examination findings include a palpable olive-shaped mass in the right upper quadrant. A peristaltic wave moving from left to right across the upper abdomen may also be seen immediately prior to emesis. Laboratory abnormalities include hypochloremic, hypokalemic metabolic alkalosis. Diagnosis is made by abdominal ultrasound, which shows an elongated, thickened pylorus. Although **pyloromyotomy** is the treatment of choice, infants with signs of dehydration or laboratory abnormalities should be admitted for **intravenous rehydration and normalization of electrolytes** prior to definitive surgical treatment. Normalization of electrolytes and correction of alkalosis prior to surgery have been shown to decrease the risk of postoperative apnea and improve overall outcomes.

Answer 143

Choanal atresia is caused by the failure of the **posterior nasal passage** to canalize during the first trimester. The condition may occur in isolation or as part of the **CHARGE syndrome** (coloboma [missing eye tissue], heart defects, atresia choanae, growth retardation, genital abnormalities, and ear abnormalities). Obstruction may be unilateral (more common) or bilateral. Although unilateral disease typically causes chronic nasal discharge in childhood, bilateral choanal atresia presents shortly after birth. Because neonates are obligate nasal breathers (ie, preferentially breathe through the nose), the complete obstruction of bilateral choanal atresia causes **intermittent cyanosis**, even at rest. If the infant's mouth is fully occluded (eg, pacifier, feeding), the resultant hypoxia and cyanosis can be profound. The increasingly distressed and hypercapnic infant will begin to **cry, relieving the airway obstruction** and normalizing perfusion. When choanal atresia is suspected, the first step is to attempt to **pass a catheter through the nares into the oropharynx**. Inability to pass the catheter is suggestive of choanal atresia. CT scan or nasal endoscopy confirms the diagnosis. Treatment includes maintaining the airway (eg, oral airway, intubation) and orogastric tube feedings until corrective surgery. Increased breathing difficulty during feeding and sleeping and improved respirations when crying.

Answer 144

Risk factors * Prematurity * Very low birth weight (\<1.5 kg [3.3 lb]) * Enteral feeding (formula riskier than breast milk) Clinical features * Vital sign instability * Lethargy * Bilious emesis, bloody stools, abdominal distension X-ray findings * **Pneumatosis intestinalis** * Portal venous gas * Pneumoperitoneum Treatment * Bowel rest, parenteral nutrition * Broad-spectrum intravenous antibiotics * ± Surgery Although the majority of affected infants are premature or have a very low birth weight, **term infants with reduced mesenteric oxygen delivery from cyanotic congenital heart disease and/or hypotension** are also at risk for intestinal ischemia and infarction. **Poor intestinal perfusion leads to enterocyte dysfunction, including impaired nutrient absorption, mucosal inflammation and necrosis, and translocation of gas-producing bacteria into the bowel wall.** Classic features of NEC include feeding intolerance, increasing abdominal girth (eg, **distension**), **bloody stools, and vomiting**. These symptoms are usually preceded by nonspecific lethargy and vital sign instability (eg, hypothermia). **Dx:** The initial diagnostic test of choice is plain film radiographs. The pathognomonic radiologic finding is **pneumatosis intestinalis**, which represents **extravasation of bowel gas into the damaged bowel wall.** Air in the portal venous system may also be seen. **Tx:** Given the risk of lethal septic shock, **empiric broad-spectrum antibiotics** should be started immediately. Severe bowel wall damage can also result in perforation and pneumoperitoneum and requires surgical intervention.

Answer 145

Risk factors * Recent viral illness or rotavirus vaccination * Pathological lead point * Congenital malformation of the intestines (eg, Meckel diverticulum) * Henoch-Schönlein purpura * Celiac disease * Intestinal tumor * Polyps Clinical presentation * Sudden, intermittent abdominal pain * “Currant jelly” stools * Sausage-shaped abdominal mass * Lethargy or altered mental status Diagnosis * “Target sign” on ultrasound Treatment * **Air 💨** or saline enema * Surgery for removal of lead point Intussusception is the telescoping of one bowel segment into the lumen of another. Affected patients experience sudden, **episodic abdominal pain** that progressively increases in frequency. Children may draw up their legs in an attempt to relieve the pain but act normally between episodes. Stools may have blood and mucus (eg, **"currant jelly"**) from bowel wall ischemia. The telescoped bowel is occasionally palpable in the shape of a cylinder or sausage and appears as a **"target sign"** on ultrasound. Most cases of intussusception (~75%) occur at age \<2 following a viral illness and have no identifiable lead point. The antecedent illness (eg, gastroenteritis) is thought to cause **hypertrophy of the Peyer patches** in the lymphoid-rich terminal ileum, thereby serving as a nidus for telescoping. Diagnosis and treatment is with air or saline enema under sonographic or fluoroscopic guidance. Surgery is indicated if enema does not reduce the intussusception or if imaging suggests a mass lesion. Early examination of the abdomen can be unremarkable, but as the problem persists, a **sausage-shaped mass** in the right upper quadrant is frequently palpated. **Dx:** **🥇 Ultrasound-guided air contrast enema,** which can lead to nonoperative reduction of the intussusception, is the procedure of choice for diagnosis and treatment. **An air, barium, or saline enema examination** under fluoroscopic or ultrasound control can be **therapeutic as well as diagnostic** when the hydrostatic effects of the contrast serve to reduce the intussusception, but should be performed with surgical backup, as a complication of attempted reduction is intestinal perforation. X-rays can show a soft tissue mass in the right upper quadrant and a crescent sign, which represents the intussusceptum projecting into large bowel gas. A "target sign" (2 concentric circles of telescoped bowel) is classically seen on ultrasound. The cause of most intussusceptions is unknown, but a Meckel diverticulum or polyp can serve as a lead point.

Answer 146

**Congenital diaphragmatic hernia (CDH)** is a defect in the diaphragm that results from incomplete fusion of the pleuroperitoneal folds during fetal development. Protrusion of abdominal contents through this defect (most commonly left-sided) into the thoracic cavity compromises lung development, leading to pulmonary hypoplasia. In utero remodeling of pulmonary vasculature also leads to arterial muscular hyperplasia and persistent pulmonary hypertension. Shortly after birth, patients develop respiratory distress (eg, tachypnea, cyanosis, retractions), often accompanied by absent breath sounds on the side of the hernia. A barrel-shaped chest and scaphoid abdomen (due to displaced abdominal contents) are characteristic findings. **Chest x-ray** is diagnostic for CDH that is not detected prenatally (eg, lack of prenatal care). Imaging shows intrathoracic bowel loops and a displaced cardiac silhouette, as seen here. Initial management includes **intubation with cautious ventilation and gastric decompression**. Urgent surgical correction is the definitive treatment. Intensive respiratory support, including high-frequency oscillatory ventilation and extracorporeal membrane oxygenation (ECMO), has increased survival. Mortality can be as high as 50% despite aggressive treatment. While surgery may correct the diaphragmatic defect, the lung on the affected side remains hypoplastic and continues to contribute to morbidity.

Answer 147

The diagnosis of Hirschsprung disease (congenital aganglionic megacolon) should be suspected in a child with intractable chronic constipation without fecal soiling (although approximately 3% do have soiling). In contrast, overflow diarrhea caused by leakage of the unformed fecal stream around a rectal impaction is common in functional constipation. A neonatal history of delayed passage of meconium is often obtained, and the infant can continue to be constipated with bouts of abdominal distention and vomiting. The infant is at risk of developing enterocolitis, a life-threatening consequence of the partial obstruction. Radiologic study by barium enema and rectal manometry are accurate diagnostic tools. Identification of an aganglionic segment of bowel by punch or suction biopsy can establish the diagnosis. Histo-chemical tissue examination showing increased amounts of acetylcholinesterase in hypertrophic nerve bundles with an absence of ganglia cells is confirmatory. Rectal manometric studies have shown that in aganglionic megacolon, the usual relaxation of the internal rectal sphincter in response to balloon inflation does not occur. Surgery is indicated as soon as the diagnosis is made. Antispasmodic agents and dietary changes are not helpful, and a plain film of the abdomen would not confirm the diagnosis. Dietary changes would only be helpful with functional constipation.

Answer 148

Pathophysiology * Incomplete closure of abdominal muscles Clinical features * Soft, nontender bulge at umbilicus * Protrudes with increased abdominal pressure * Typically reducible Management * Observe for spontaneous closure * Elective surgery around age 5 A congenital umbilical hernia is due to incomplete closure of the abdominal muscles around the umbilical ring at birth. It is commonly associated with hypothyroidism and Ehlers-Danlos, Beckwith-Wiedemann, and Down syndromes, but also occurs frequently in normal newborns. Physical examination shows a soft, nontender bulge covered by skin that protrudes with increased abdominal pressure (eg, crying, straining). The hernia may contain omentum or portions of the small intestine. Most umbilical hernias are reduced easily through the umbilical ring with very low risk of incarceration and strangulation. **Small umbilical hernias** typically **close spontaneously** as the rectus abdominis muscles grow together and fascial layers fuse. Spontaneous closure is less likely with large (\>1.5 cm diameter) hernias or in patients with underlying medical problems. 🔪Surgery is recommended around **age 5** for persistent hernias, or sooner if complications occur.

Answer 149

Gastroesophageal reflux is a common pediatric complaint, often seen in the first 1 to 2 months of life and resolving by 1 to 2 years of age. Occasional episodes of gas troesophageal reflux in infancy are physiologic; gastroesophageal reflux disease (GERD) is the pathologic form, involving respiratory symptoms, esophagitis, related apnea, or weight loss. Sandifer syndrome is the bending or aching of the neck caused by gastroesophageal reflux; this condition may be confused with infantile spasm. About 7% of children have reflux severe enough to require medical attention, and only 2% of that group requires investigation. For children who are growing well and do not have respiratory symptoms attributed to reflux, conservative treatment (small feeds, thickened formula, avoiding high-fat meals and overfeeding, etc) suffices. A small number need pharmacologic therapy. Medications to treat GERD include acid blockade with H2 blockers or proton pump inhibitors, resulting in decreased esophagitis. Prokinetic agents are frequently used in conjunction with acid blockade for this illness, but have not been consistently shown to decrease symptoms. Pyloric stenosis presents with nonbilious vomiting in the first weeks of life and not at 12 months of age. Similarly, a patient with a partial duodenal atresia would be noted in the newborn period, likely with bilious vomiting. Hypothyroidism can cause constipation, among other findings, but a presenation with isolated vomiting would be distinctly unusual. A 12-month-old patient with a tracheoesophageal fistula would likely have an “H-type” fistula, which presents with ongoing respiratory issues and not emesis.

Answer 150

gastroesophageal reflux, causing , a condition in which infants will arch and become tonic to protect their airway from the refluxing gastric contents. While an upper GI series can sometimes diagnose gastroesophageal reflux, esophageal pH probe is currently the preferred diagnostic test.

Answer 151

Vascular rings encompass congenital malformations of the aortic arch system that encircle the **trachea** and/or **esophagus** and cause compressive symptoms. Tracheal compression leads to **biphasic stridor** that increases with increased work of breathing (eg, crying, feeding). Vascular rings can also present with esophageal compression symptoms, with severe solid-food **dysphagia**. CT scan can delineate the anatomy forming the vascular ring and evaluate associated tracheal abnormalities. Due to possible concurrent cardiac and airway abnormalities, patients require **direct laryngoscopy, bronchoscopy, and echocardiogram**. Treatment is **surgical** division of the structures creating the ring.

Answer 152

Midgut volvulus classically presents in a neonate (age \<1 month) with **bilious vomiting**. Initially, the abdomen is soft and not distended, but ischemia of the twisted bowel can cause bloody stools, bowel perforation, abdominal distension, and peritonitis. Signs of ischemia or systemic decompensation (ie, shock) are an indication for emergency laparotomy. The evaluation of clinically stable neonates with bilious emesis begins with cessation of enteral feeds, nasogastric (NG) tube decompression, and intravenous (IV) fluids. An x-ray is generally the first step to rule out pneumoperitoneum, which would reflect intestinal perforation and immediate need for emergency surgery. Rarely, the diagnosis may be suspected if the NG tube terminates in the abnormally-placed duodenum, but x-ray is usually nonspecific for midgut volvulus. If there is no evidence of free air and the bowel gas pattern is not suggestive of duodenal atresia ("double bubble") or distal obstruction (dilated loops of bowel), then an upper gastrointestinal (GI) series (eg, barium swallow) should be performed. An upper GI series is the fastest and most accurate method of diagnosing malrotation with midgut volvulus. The finding of the Ligament of Treitz on the right side of the abdomen reflects malrotation while contrast in a "corkscrew" pattern indicates volvulus. Surgery must be expedited to prevent catastrophic complications. If present, the volvulus is reduced. The Ladd procedure consists of fixing the bowel in a non-rotated position to minimize recurrent volvulus risk.

Answer 153

Rumination is an uncommon disorder in which patients will regurgitate, rechew, and reswallow food. Initially described in infants with mental retardation and institutionalized patients, rumination may also be present in otherwise normal children who have problem relationships with their caregivers. One hypothesis suggests the regurgitation behavior begins as a self-stimulus, with infants putting their hands in their mouth and gagging themselves. The behavior is reinforced with the attention they receive for the regurgitation. Rumination may also be seen in adolescents, and may be misdiagnosed as bulimia. While some studies have suggested an association, bulimic patients do not typically reswallow their food. Current information suggests that neither antireflux nor psychiatric medications have any beneficial effects on these patients. Instead, treatment must be focused on removing the attention paid by the caregivers to the rumination, and reinforcing proper eating behaviors. The child’s weight loss makes observation inappropriate, and surgery is not effective in this condition. Inhaled corticosteroids may be useful in a patient with eosinophilic esophagitis, but not in the patient in this vignette.

Answer 154

The development of jaundice in a healthy full-term baby may be considered the result of a normal physiologic process in certain circumstances. It may be normal if the time of onset and duration of the jaundice and the pattern of serially determined serum concentrations of bilirubin are in conformity with currently accepted safe criteria. **Physiologic jaundice** becomes apparent on the second or third day of life, peaks to levels no higher than about **12 mg/dL on the fourth or fifth day**, and disappears by the end of the first week of life. The rate of rise is **less than 5 mg/dL per 24 hours** and levels of conjugated bilirubin do not exceed about 1 mg/dL. Almost all newborns on days 2-4 of life have physiologic jaundice due to **indirect hyperbilirubinemia**. The following physiologic differences in bilirubin metabolism account for this finding: 1. At birth, fetal red blood cells (RBCs) are increased (hematocrit 50%-60%) with a shortened life span (90 days), resulting in high RBC turnover and increased bilirubin production. 2. Hepatic bilirubin clearance is decreased because uridine diphosphogluconurate glucuronosyltransferase (UGT) activity does not reach adult levels until age 2 weeks. This hepatic enzyme conjugates bilirubin, making it soluble (ie, excretable). Eastern Asian newborns have decreased UGT compared to that of other ethnicities. 3. Enterohepatic recycling is increased because the low bacterial load in the newborn gut results in slower conversion of bilirubin to urobilinogen for fecal excretion. Physiologic jaundice of the newborn is benign and resolves by age 1-2 weeks. Frequent feeding promotes gut colonization and fecal excretion. Phototherapy may be indicated for rapidly rising levels of bilirubin to prevent kernicterus. **Breastfeeding jaundice** (breastfeeding failure jaundice), refers to exaggerated **unconjugated (indirect \> direct) hyperbilirubinemia** in the **first week of life** that is caused by insufficient intake of breast milk. The decreased enteral intake leads to delayed stooling (ie, decreased bilirubin elimination) and increased enterohepatic circulation. Poor intake also causes dehydration (eg, decreased urinary output, excessive weight loss), which in turn leads to decreased bilirubin delivery to the liver and decreased conjugation, thereby exacerbating the unconjugated hyperbilirubinemia and jaundice. Breastfeeding challenges leading to insufficient breast milk intake can result from: * Maternal factors: Delayed milk production or inadequate milk supply; **infrequent feeding**; cracked/clogged nipples * Infant factors: Poor latch (eg, due to breast engorgement); ineffective suck; falling asleep In the first few days of life, exclusively breastfed infants actually consume colostrum (stage I lactogenesis/secretory initiation); maternal milk production (stage II lactogenesis/secretory activation) should increase significantly during the first 48-72 hours of life when infants are frequently brought to the breast for suckling. On average, exclusively breastfed newborns should feed for **≥10-20 minutes per breast every 2-3 hours**. During the first week of life, the number of wet diapers a day should equal at least the infant's age in days (eg, a 4-day-old infant should have ≥4 wet diapers a day). **Healthy neonates normally lose up to 7% of their birth weight in the first 5 days of life due to excretion of excess fluid acquired in utero and during labor.** Signs of dehydration include dry mucous membranes, a sunken fontanelle, and decreased urine output. As a general rule, the number of wet diapers should equal age in days for the first week of life. For example, a 4-day-old neonate should have \>4 wet diapers per day. After the first week, infants should have \>6 wet diapers per day. **Birth weight should be regained by age 10-14 days.** **Breast milk jaundice** occurs in breastfed infants whose physiologic jaundice (due to normal changes in neonatal bilirubin metabolism) persists **beyond the first week of life**. Breast milk jaundice may be due to **high levels of β-glucuronidase in breast milk**, which deconjugate intestinal bilirubin and increase enterohepatic circulation. Unlike infants with breastfeeding jaundice, those with breast milk jaundice do not have signs of dehydration or feeding difficulty. * **Starts at age 3-5 days;** * **peaks at 2 weeks** * **High levels of β-glucuronidase in breast milk deconjugate intestinal bilirubin & increase enterohepatic circulation** * Adequate breastfeeding * Normal examination **Cx:** Concern about neonatal jaundice relates to the risk of the **neurotoxic effects of unconjugated bilirubin**. The precise level and duration of exposure necessary to produce toxic effects are not known, but bilirubin encephalopathy, or **kernicterus**, is rare in term infants whose bilirubin level is kept below 18 to 20 mg/dL.

Answer 155

Cholecystitis and cholelithiasis are unusual diseases in children and are almost always associated with predisposing disorders such as hemolytic anemia, pregnancy, CF, Crohn disease, obesity, rapid weight loss, or prior ileal resection. Pain of the right upper quadrant, nausea, vomiting, fever, and jaundice are symptoms of acute cholecystitis. The diagnosis is confirmed with an ultrasound of the gallbladder. While some of the other answers listed might result in abnormalities, the findings would be neither sensitive nor specific for cholecystitis. Thus, the diagnostic test of choice is an ultrasound.

Answer 156

**Obstructive jaundice** (ie, direct-reacting bilirubin greater than 20% of the total) requires investigation in all infants. CF and α1-antitrypsin deficiency should be considered in the diagnostic evaluation of any child with obstructive jaundice. Other diseases to be excluded are galactosemia, tyrosinemia, and urinary tract or other infections (including toxoplasmosis, cytomegalovirus, rubella, syphilis, and herpesvirus). Ultrasound examination to rule out choledochal cyst may be included with a 99mTc hepatic iminodiacetic acid (HIDA) scan to assess the patency of the biliary tree. Liver biopsy can assist in the diagnosis by providing a histologic diagnosis (eg, hepatitis, biliary atresia), tissue for enzyme activity (ie, inborn error of metabolism), or tissue for microscopic determination of storage diseases. ABO and Rh incompatibility occasionally cause direct hyperbilirubinemia if there were brisk hemolysis at birth, which would then lead to inspissated bile syndrome. All of the other causes listed typically lead to indirect hyperbilirubinemia.

Answer 157

Risk factors * Initiation of solid food & cow’s milk * Toilet training * School entry Clinical features * Painful/hard bowel movements * Stool withholding * Encopresis Complications * Anal fissures * Hemorrhoids * Enuresis/urinary tract infections Treatment * ↑ Dietary fiber & water intake * Limit cow’s milk intake to \<24 oz * Laxatives * ± Suppositories, enema Recurrent cystitis in toddlers is often caused by constipation as fecal retention can cause rectal distension, which in turn compresses the bladder and prevents complete voiding. The residual urine is a potential breeding ground for bacteria that ascend to the urethra from the perineum. Risk factors of constipation include dietary changes, such as transition from breast milk to cow's milk and solid foods. Signs of constipation include straining or pain with defecation, passage of firm pellet-like stools, and anal fissures and hemorrhoids. Prevention and treatment of recurrent cystitis requires adequate treatment of constipation.

Answer 158

Risk factors * First-degree relative with celiac disease * Autoimmune disorders * Down syndrome Clinical features * Abdominal pain, bloating, diarrhea * Failure to thrive, short stature * Dermatitis herpetiformis Workup * ↑ Tissue transglutaminase IgA antibody * Intestinal biopsy (villous atrophy) Treatment * Gluten-free diet Celiac disease is an immune-mediated hypersensitivity to gluten leading to impaired nutrient absorption in the proximal small intestine. Classic celiac disease presents with gastrointestinal symptoms of abdominal pain, nausea, vomiting, diarrhea, and/or weight loss. Adolescents and adults may have extraintestinal symptoms such as fatigue, iron deficiency anemia (microcytic anemia, low ferritin), and **dermatitis herpetiformis**. Iron deficiency anemia in celiac disease is attributed to **poor iron absorption** secondary to duodenal villous atrophy. Iron supplementation can be considered after an underlying cause is confirmed and would likely improve anemia in celiac disease after initiation of a gluten-free diet. Dermatitis herpetiformis, a pruritic papular or vesicular rash associated with celiac disease, is located on the knees, elbows, forearms, and buttocks. Celiac disease is associated with other autoimmune conditions (eg, type I diabetes, thyroiditis); it should be screened for in this diabetic patient with an anti-tissue transglutaminase antibody IgAlevel, followed by endoscopic duodenal biopsy for confirmation.

Answer 159

Pathogenesis * Extrahepatic bile duct fibrosis Clinical findings * Infants age 2-8 weeks * Jaundice, acholic stools, dark urine * **Direct hyperbilirubinemia** Diagnostic evaluation * Ultrasound of the right upper quadrant * Absent/abnormal gallbladder and/or CBD * Liver biopsy * Intrahepatic bile duct proliferation * Portal tract edema * Fibrosis * Intraoperative cholangiography * Biliary obstruction Treatment * Surgical hepatoportoenterostomy (Kasai procedure) * Liver transplant BA is characterized by progressive fibrosis and obliteration of the **extrahepatic bile ducts.** Bilirubin (bile pigment) continues to be conjugated by the liver but cannot be excreted by the biliary system, leading to cholestasis. Symptoms typically manifest at age 2-8 weeks with jaundice and scleral icterus. **Acholic stools (eg, light yellow, clay-colored, white)** often occur because bile cannot reach the intestines, and **urine may be dark yellow due to bilirubinuria.** Laboratory evaluation reveals elevated direct bilirubin, often with normal or mildly elevated aspartate aminotransferase and alanine aminotransferase. **Dx:** Characteristic ultrasound findings include **an abnormal/absent gallbladder, absent common bile duct, and triangular cord sign (fibrous remnants seen above the porta hepatis).** Liver biopsy is used to help distinguish BA from other cholestatic conditions (eg, Alagille syndrome) and typically reveals intrahepatic duct proliferation, portal tract edema, and fibrosis. Biliary obstruction on **intraoperative cholangiography** is the gold standard for diagnosis; if it is present, immediate hepatoportoenterostomy (Kasai procedure) is performed to reestablish bile flow to the small intestine.

Answer 160

A biliary cyst (or choledochal cyst) is a dilatation of the biliary tree. These dilatations may be single or multiple and can be intra- or extrahepatic. The most common type of biliary cyst (type I) is a single, extrahepatic cyst. Biliary cysts can be congenital or acquired. Classic signs of a biliary cyst include abdominal pain, jaundice (due to obstructive cholestasis), and a palpable mass. However, the clinical presentation varies with age. The majority of patients are **age \<10**. Infants can have **jaundice** and **acholic stools**, a presentation that resembles biliary atresia. Older children may have **pancreatitis**. Adults with biliary cysts commonly present with vague epigastric or right upper quadrant abdominal pain or **cholangitis**. The diagnosis is generally made by ultrasound or other imaging; endoscopic retrograde cholangiopancreatography may be needed if obstruction is suspected. Biliary cysts can transform into cholangiocarcinoma. Surgical resection relieves the obstruction and reduces the risk of malignancy.

Answer 161

Refeeding syndrome is the constellation of pathologic derangements resulting from a surge in insulin activity as the body resumes anabolism. Carbohydrate ingestion, whether enteral or intravenous, causes pancreatic insulin secretion and cellular uptake of phosphorus, potassium, and magnesium. **Phosphorus** is the primary deficient electrolyte as it is required for energy (adenosine triphosphate). Deficiencies in **potassium and magnesium** potentiate **cardiac arrhythmias** in a heart that is already atrophic from prolonged malnutrition. Therefore, aggressive initiation of nutrition without adequate electrolyte repletion can quickly precipitate cardiopulmonary failure.

Answer 162

Hepatic hemangioma is the most common benign liver tumor, is often found incidentally during imaging for other conditions. However, triphasic CT scan will reveal centripetal enhancement (ie, enhancement moving from periphery to center) and no central scar.

Answer 163

Caused by mechanical obstruction, leading to postprandial pain and vomiting with early satiety. Common causes of gastric outlet obstruction include gastric malignancy, peptic ulcer disease, Crohn disease, strictures (with pyloric stenosis) secondary to ingestion of caustic agents, and gastric bezoars. Acid ingestion causes fibrosis 6-12 weeks after the resolution of the acute injury. Physical examination can show an abdominal **succussion splash**, which is elicited by placing the stethoscope over the upper abdomen and rocking the patient back and forth at the hips. Retained gastric material \>3 hours after a meal will generate a splash sound and indicates the presence of a hollow viscus filled with both fluid and gas. Upper endoscopy is usually required to confirm the diagnosis, and treatment is primarily surgical.

Answer 164

Etiology * Anatomical abnormalities (eg, strictures, surgery) * Motility disorders (eg, diabetes mellitus, scleroderma) Signs/symptoms * Abdominal pain, diarrhea, bloating, flatulence * Malabsorption, weight loss, anemia, vitamin deficiency Diagnosis * Jejunal aspirate & culture showing \>105 organisms/mL * Carbohydrate breath testing (eg, lactulose, glucose) Organisms * Streptococci, Bacteroides, Escherichia, Lactobacillus Treatment * Antibiotics (eg, rifaximin, amoxicillin-clavulanate) * Avoid antimotility agents (eg, narcotics) * Dietary changes (eg, high-fat, low-carbohydrate) * Promotility agents (eg, metoclopramide) The proximal small intestine normally contains minimal bacterial colonization due to gastric acidity and peristalsis; however, **gastric bypass procedures** (Roux-en-Y gastric bypass) **result in a blind loop of intestine that allows for excessive bacterial growth**. Conditions that alter intestinal motility (eg, systemic sclerosis, diabetes mellitus), anatomy (eg, strictures), or gastric/pancreatic secretions (eg, atrophic gastritis, chronic pancreatitis) also predispose to SIBO. Patients with SIBO typically develop bloating, flatulence, abdominal discomfort, and watery diarrhea; in severe cases, malabsorption (eg, steatorrhea) and weight loss are seen. Laboratory studies are frequently normal but may demonstrate nutritional deficiencies (eg, vitamin B12, fat-soluble vitamins) and associated **macrocytic anemia**. Diagnostic tests include carbohydrate breath tests (eg, lactulose, glucose) that measure the production of hydrogen by intestinal flora. Endoscopy with jejunal aspirate and culture showing increased bacterial burden are also used. Management involves correction of the underlying abnormality, dietary modification, and a short course of empiric antibiotics (eg, rifaximin).

Answer 165

Etiology * Pediatric aspirin use during influenza or varicella infection Clinical features * Acute liver failure * Encephalopathy Laboratory findings * ↑ AST, ALT * ↑ PT, INR, PTT * ↑ NH3 Treatment * Supportive Reye syndrome is characterized by encephalopathy and acute liver failure after a viral infection. The incidence declined significantly after the 1980s due to widespread education about **salicylate (eg, aspirin) avoidance** in children and adolescents, especially during viral infections. Most cases occur with aspirin use in the setting of influenza B (most common), influenza A, or varicella zosterinfection. Aspirin is a **mitochondrial toxin** that can cause **acute hepatic dysfunction** in young individuals. Clinical features of hepatic dysfunction include nausea, vomiting, and hepatomegaly. Laboratory derangements include elevated transaminases, coagulopathy (prolonged PT, INR, and PTT), and hyperammonemia. Excess ammonia is neurotoxic and causes cerebral edema and encephalopathy (eg, mental status changes). A diagnosis of Reye syndrome is rare but potentially life-threatening (~30% mortality). The presence of **microvesicular steatosis** on liver biopsy in the context of acute hepatic encephalopathy is consistent with Reye syndrome. Parents should be reminded that aspirin is generally contraindicated in children, except in the treatment of Kawasaki disease and rheumatologic diseases (eg, juvenile idiopathic arthritis).