Bowel Diseases I Flashcards
Malabsorption diseases
Celiac disease Whipple disease Bacterial overgrowth Short bowel syndrome Lactase Deficiency
Celiac disease (aka- sprue, celiac sprue, and gluten enteropathy)
- a permanent dietary disorder caused by an immunologic response to gluten (a storage protein found in certain grains)
- it results in diffuse damage to the proximal small intestinal mucosa with malabsorption of nutrients
S/S of celiac disease depend on the length of small intestine involved and the patient’s age
“Classic” symptoms are….
Malabsorption
Diarrhea, steatorrhea, weight loss, abdominal distention, weakness, muscle wasting, or growth retardation (kids)
Skin finding associated with Celiacs is
KNOW FOR EXAM
Dermatitis herpetaformus
-red blotches, itchy, uncomfortable (seen all over body, butt, back, shoulders)
Lab findings associated with Celiac’s (list 10)
- Microcytic anemia due to iron deficiency
- Megaloblastic anemia due to folate or vitamin B12 deficiency
- Low serum calcium
- Elevated alkaline phosphatase
- Elevations of prothrombin time
- Decreased vitamin A & D
- Low serum albumin
- Nonanion gap acidosis
- Hypokalemia
- Mild elevations of aminotransferases
If patient has Steatorrhea (bulky, light-colored stools), lab findings will show ________
(Celiacs)
-Increased fecal fat; decreased serum cholesterol; decreased serum carotene, vitamin A, vitamin D
Malabsorbed: Triglycerides, fatty acids, phospholipids, cholesterol, fat soluble vitamins: A, D, E, K
If patient has Diarrhea (increased fecal water), lab findings will show ________
(Celiacs)
-Increased stool volume and weight; increased fecal fat; increased stool osmolality gap
Malabsorbed: Fat, carbs
If patient has Weight loss; muscle wasting, lab findings will show ________
(Celiacs)
-Increased fecal fat; decreased carbohydrate (D-xylose) absorption
Malabsorbed: Fat, protein, carbs
If patient has Microcytic anemia, lab findings will show ________
(Celiacs)
Low serum Iron
Malabsorbed: Iron
If patient has Macrocytic anemia, lab findings will show ________
(Celiacs)
Decreased serum vitamin B12 or red blood cell folate
Malabsorbed: Vitamin B12 or folic acid
If patient has Paresthesia; tetany; positive Trousseau and Chvostek signs, lab findings will show ________
(Celiacs)
Decreased serum calcium or magnesium
Malabsorbed: Calcium, vitamin D, magnesium
If patient has Bone pain; pathologic fractures; skeletal deformities, lab findings will show ________
(Celiacs)
Osteopenia on radiograph; osteoporosis (adults); osteomalacia (children)
Malabsorbed: Calcium, vit D
If patient has Bleeding tendency (ecchymoses, epistaxis), lab findings will show ________
(Celiacs)
Prolonged prothrombin time or INR
Malabsorbed: vit K
If patient has Bleeding tendency (ecchymoses, epistaxis), lab findings will show ________
(Celiacs)
Decreased serum total protein and albumin; increased fecal loss of alpha-1-antitrypsin
Malabsorbed: protein
If patient has Milk intolerance (cramps, bloating, diarrhea), lab findings will show ________
(Celiacs)
Abnormal lactose tolerance test
Malabsorbed: lactose
Antibody for Celiacs
IgA tissue transglutaminase (IgA tTG) antibody
-Antigliadin antibodies and
IgA antiendomysial antibodies are NOT recommended
Gold standard method for confirmation of the diagnosis in patients with a positive serologic test for celiac disease or patients with negative serologies when symptoms and laboratory studies are strongly suggestive of celiac disease
Endoscopic mucosal biopsy of the proximal duodenum (bulb) and distal duodenum
With celiacs, what is observed in endoscopic mucosal biopsy of proximal and distal duodenum?
-Atrophy or scalloping of the duodenal folds may be observed (see less folding, looks smooth, google image)
-Histology reveals abnormalities ranging from intraepithelial lymphocytosis alone to extensive infiltration of the lamina propria with lymphocytes and plasma cells with hypertrophy of the intestinal crypts and blunting or complete loss of intestinal villi
(CLASSIC- know histo image for this FOR EXAM!)
Treatment for Celiacs
- Removal of all gluten from the diet is essential to therapy: all wheat, rye, and barley
- Most patients with celiac disease also have lactose intolerance either temporarily or permanently and should avoid dairy products
- Dietary supplements (folate, iron, calcium, and vitamins A, B12, D, and E) initially
- Confirmed osteoporosis may require long-term calcium, vitamin D, and bisphosphonate therapy
- Excellent prognosis
Celiacs is associated with other autoimmune disorders including
Addison disease, Graves disease, type 1 diabetes mellitus, myasthenia gravis, scleroderma, Sjögren syndrome, atrophic gastritis, and pancreatic insufficiency
-Celiac disease that is truly refractory to gluten withdrawal occurs in less than 5% and generally carries a poor prognosis
Whipple Disease
- Rare multisystem illness caused by infection with the bacillus Tropheryma whippelii
- Most commonly affects white men in the fourth to sixth decades
Symptoms associated with Whipple Disease
- Arthralgias (80%, migratory, nondeforming)
- Diarrhea, abdominal pain (75%)
- Weight loss (almost 100%) with protein-losing enteropathy, hypoalbuminemia and edema
- Intermittent low-grade fever (50%) of cases
- Generalized lymphadenopathy
Cardiac involvement of Whipples
Heart failure
Valvular regurgitation
CNS involvement of Whipples
- Dementia, lethargy, coma, seizures, myoclonus, or hypothalamic signs
- Ophthalmoplegia, nystagmus
Common S/S of Whipples
- Low-grade fever
- Malabsorption
- Lymphadenopathy
- Heart murmurs
- Peripheral joints edema, erythema
- Neurological findings
- Hyperpigmentation on sun-exposed areas
- Hypotension** (VERY late manifestation)
Endoscopic biopsy of the duodenum with histologic evaluation during Whipples shows
-Infiltration of the lamina propria with PAS-positive (“foamy”) macrophages that contain gram-positive bacilli (which are not acid-fast) and dilation of the lacteals
“Foamy whipped cream in a CAN” (cardiac, arthralgias, neuro)
Whipple bacillus has a characteristic ________ appearance on electron microscopy
trimellar wall
Because asymptomatic central nervous system infection occurs in 40% of patients, ___________
examination of the cerebrospinal fluid by PCR for T whippelii should be performed routinely
Treatment of Whipple Disease
- Antibiotic therapy results in a dramatic clinical improvement within several weeks
- Complete clinical response usually is evident within 1–3 months
- Relapse may occur in up to one-third of patients after discontinuation of treatment
- Prolonged treatment for at least 1 year is required
- Drugs that cross the blood-brain barrier are preferred
- If untreated, the disease is fatal
- Prevent neurological progression
Overgrowth- Bacterial deconjugation of bile salts may lead to inadequate micelle formation, resulting in
decreased fat absorption with steatorrhea and malabsorption of fat-soluble vitamins (A, D)
Microbial uptake of specific nutrients reduces
absorption of vitamin B12 and carbohydrates
Bacterial proliferation also causes
direct damage to intestinal epithelial cells and the brush border, further impairing absorption of proteins, carbohydrates, and minerals
Passage of the malabsorbed bile acids and carbohydrates into the colon leads to
an osmotic and secretory diarrhea and increased flatulence
Causes of bacterial overgrowth
- Gastric achlorhydria, from PPIs
- Anatomic abnormalities of the small intestine with stagnation
- Small intestine motility disorders
- Gastrocolic or coloenteric fistula
- Miscellaneous disorders
S/S of bacterial overgrowth
- Many asymptomatic
- Flatulence
- Weight loss
- Abdominal pain
- Diarrhea
- Steatorrhea
- Vitamin and mineral deficiencies (fat-soluble vitamins A or D, vitamin B12, and iron)
Gold standard for diagnosis of bacterial overgrowth is ________, but most people use ___________
-Gold standard for diagnosis: aspirate and culture of proximal jejunal secretion that demonstrates over 105 organisms/mL
- Noninvasive breath tests are easier to perform (most people use this, less invasive)
- Breath hydrogen and methane tests with glucose or lactulose
- Empiric antibiotic trial* (older way of thinking, don’t want to blindly give antibiotics)
Treatment for bacterial overgrowth
- Fix anatomic defect if one exists
- 1–2 weeks with oral broad-spectrum antibiotics effective against enteric aerobes and anaerobes usually leads to dramatic improvement
- In patients w/ symptoms that recur off antibiotics, use cyclic therapy; continuous antibiotics should be avoided, if possible, to avoid development of bacterial antibiotic resistance.
Short Bowel Syndrome
- Malabsorptive condition that arises secondary to removal of significant segments of the small intestine:
- Crohn disease
- Mesenteric infarction
- Radiation enteritis
- Volvulus
- Tumor resection
- Trauma
- Type and degree of malabsorption depend on the length and site of the resection and the degree of adaptation of the remaining bowel
Resection of the terminal ileum- Malabsorption of bile salts and vitamin B12; Low serum vitamin B12 levels or resection of over ____ of ileum require monthly subcutaneous or intramuscular vitamin B12 injections
50 cm
In patients with less than ____ of ileal resection, bile salt malabsorption stimulates fluid secretion from the colon, resulting in watery diarrhea treated with bile salt-binding resins
100 cm
Resection of ______ of ileum leads to a reduction in the bile salt pool that results in steatorrhea and malabsorption of fat-soluble vitamins…treatment is with a low-fat diet and vitamins supplemented with medium-chain triglycerides
over 100 cm
Unabsorbed fatty acids bind with _______, reducing its absorption and enhancing the absorption of oxalate and oxalate kidney stones may develop
calcium
-Calcium supplements should be administered to bind oxalate and increase serum calcium
Lactase is a brush border enzyme that hydrolyzes the disaccharide lactose into
glucose and galactose
-Lactase deficiency may also arise secondary to other gastrointestinal disorders that affect the proximal small intestinal mucosa (Crohn disease, sprue, viral gastroenteritis, giardiasis, short bowel syndrome, and malnutrition)
A large number of false self diagnosis- Most patients with lactose intolerance can drink one or two 8 oz glasses of milk daily without symptoms if taken with food at wide intervals
Mild to moderate amounts of lactose malabsorption causes
Bloating, abdominal cramps, and flatulence
-Higher lactose ingestions patients will experience osmotic diarrhea
- By spreading dairy product intake throughout the day in quantities of less than 12 g of lactose (one cup of milk), most patients can take dairy products without symptoms and do not require lactase supplements
- can take lactase enzymes
- may need calcium supplement
Intestinal motility disorders
- Acute paralytic ileus
- Acute colonic pseudo-obstruction (Ogilvie Syndrome)
- Chronic Intestinal Pseudo-obstruction & Gastroparesis
Acute Paralytic Ileus
Ileus is a condition in which there is neurogenic failure or loss of peristalsis in the intestine in the absence of any mechanical obstruction
Causes of Acute Paralytic Ileus
- Intra-abdominal processes such as recent gastrointestinal or abdominal surgery or peritoneal irritation
- Severe medical illness such as pneumonia, respiratory failure requiring intubation, sepsis or severe infections, uremia, diabetic ketoacidosis, and electrolyte abnormalities can lead to Ileus
- Medications that affect intestinal motility (opioids, anticholinergics, phenothiazines)
- Following surgery, small intestinal motility usually normalizes first (often within hours), followed by the stomach (24–48 hours), and the colon (48–72
S/S of Acute Paralytic Ileus
- Mild diffuse, continuous abdominal discomfort with nausea and vomiting
- Generalized abdominal distention is present with minimal abdominal tenderness but no signs of peritoneal irritation
- Bowel sounds are diminished to absent
- Laboratory abnormalities are attributable to the underlying condition
Plain film radiography of the abdomen shows
distended gas-filled loops of the small and large intestine; air-fluid levels may be seen
-CT scan may be useful in such instances to exclude mechanical obstruction, especially in postoperative patients
Drug that reverses opioid-induced inhibition of intestinal motility
Alvimopan is a peripherally acting mu-opioid receptor antagonist with limited absorption or systemic activity
Ogilvie Syndrome
- Extremely dangerous and hard to treat
- Spontaneous MASSIVE dilation of the cecum and proximal colon may occur in a number of different settings in hospitalized patients
- Progressive cecal dilation may lead to spontaneous perforation with dire consequences
- KNOW XRAY PICS*
Colonic pseudo-obstruction like Ogilvie’s is most commonly detected in
postsurgical patients (mean 3–5 days), after trauma, and in medical patients with respiratory failure, metabolic imbalance, malignancy, myocardial infarction, heart failure, pancreatitis, or a recent neurologic event
Liberal use of _________ may precipitate colonic pseudo-obstruction in susceptible patients. It may also occur as a manifestation of colonic ischemia.
Etiology of colonic pseudo-obstruction is unknown.
opioids or anticholinergic agents
S/S of Ogilvie Syndrome
- Abdominal distention is first sign
- Some patients are asymptomatic
- Most report constant but mild abdominal pain
- Nausea and vomiting may be present
- Bowel movements may be absent, but up to 40% of patients continue to pass flatus or stool
- Laboratory findings reflect the underlying medical or surgical problems
- Significant fever or leukocytosis raises concern for colonic ischemia or perforation
Once you notice extreme distention and patient is getting fever/high white count, worry about ______
the bowel becoming ischemic
During Ogilvie, radiographs show
colonic dilation, usually confined to the cecum and proximal colon
- Because the dilated appearance of the colon may raise concern that there is a distal colonic mechanical obstruction due to malignancy, volvulus, or fecal impaction, a CT scan or water-soluble enema may sometimes be performed.
- *EVERYTHING must be ruled out before diagnosing with Ogilvie syndrome**
First step in treating Ogilvie
- Conservative treatment is the appropriate first step for patients with no or minimal abdominal tenderness, no fever, no leukocytosis, and a cecal diameter smaller than 12 cm
- Treat underlying illness
- A nasogastric tube and a rectal tube should be placed
Patient positioning with Ogilvie
- Patients should be ambulated or periodically rolled from side to side and to the knee-chest position in an effort to promote expulsion of colonic gas
- All drugs that reduce intestinal motility should be discontinued if possible
- Enemas may be administered judiciously if large amounts of stool are evident on radiography
Laxatives or Ogilvie?
NO (may cause perforation, pain, or electrolyte abnormalities)
Patients with Ogilvie must be watched for signs of worsening distention or abdominal tenderness; cecal size should be assessed by _________
abdominal radiographs every 12 hours
Intervention should be considered in patients with any of the following:
- No improvement or clinical deterioration after 24–48 hours of conservative therapy
- Cecal dilation greater than 10 cm for a prolonged period (more than 3–4 days)
- Patients with cecal dilation greater than 12 cm
- Neostigmine injection should be given unless contraindicated
- Colonoscopic decompression is indicated in patients who fail to respond to neostigmine
Gastroparesis and chronic intestinal pseudo-obstruction are chronic conditions characterized by
intermittent, waxing and waning symptoms and signs of gastric or intestinal obstruction in the absence of any mechanical lesions to account for the findings
Gastroparesis and chronic intestinal pseudo-obstruction are caused by
a heterogeneous group of endocrine disorders, postsurgical conditions, neurologic conditions, rheumatologic syndromes, infections, amyloidosis, paraneoplastic syndromes, medications, eating disorders, and idiopathic
S/S of Gastroparesis and chronic intestinal pseudo-obstruction
- Small bowel involvement: abdominal distention, vomiting, diarrhea, and varying degrees of malnutrition can result in constipation or alternating diarrhea and constipation
- Gastric involvement: Chronic or intermittent symptoms of postprandial fullness (early satiety), nausea, and vomiting (1–3 hours after meals)
With Gastroparesis and chronic intestinal pseudo-obstruction, plain film radiography may show
dilation of the esophagus, stomach, small intestine, or colon resembling ileus or mechanical obstruction
______ is much more common than gastroparesis or intestinal pseudo-obstruction and must be excluded
Mechanical obstruction of the stomach, small intestine, or colon
Optimal means for assessing gastric emptying?
Gastric scintigraphy with a low-fat solid meal
Small bowel manometry is useful for
distinguishing visceral from myopathic disorders and for excluding cases of mechanical obstruction
Treatment for Chronic Intestinal Pseudo-obstruction & Gastroparesis
- No specific therapy for gastroparesis or pseudo-obstruction
- Acute exacerbations are treated with nasogastric suction and intravenous fluids
- Long-term treatment is directed at maintaining nutrition
- Agents that reduce gastrointestinal motility should be avoided
Drugs for Chronic Intestinal Pseudo-obstruction & Gastroparesis
- Metoclopramide and erythromycin before meals are each of benefit in treatment of gastroparesis but NOT small bowel dysmotility
- Domperidone is another antidopaminergic agent that enhances gastric emptying and has efficacy as an antiemetic agent- not approved in US currently but works well
Appendicitis
- Most common abdominal surgical emergency, affecting approximately 10% of the population
- Most commonly between the ages of 10 and 30 years
- Initiated by obstruction of the appendix by a fecalith, inflammation, foreign body, or neoplasm
- Obstruction leads to increased intraluminal pressure, venous congestion, infection, and thrombosis of intramural vessels
If appendicitis goes untreated __________
gangrene and perforation develop within 36 hours**
S/S of Appendicitis
- Begins with vague, often colicky periumbilical or epigastric pain
- Within 12 hours the pain shifts to the right lower quadrant, manifested as a steady ache that is worsened by walking or coughing
- Almost all patients have nausea with one or two episodes of vomiting
- Low-grade fever
- Localized tenderness with guarding in the right lower quadrant at McBurney’s point
2 positive signs with Appendicitis
- Psoas sign (pain on passive extension of the right hip)
2. Obturator sign (pain with passive flexion and internal rotation of the right hip)
Atypical presentations of appendicitis
Retrocecal appendix
In the elderly
In pregnancy
The treatment of early, uncomplicated appendicitis is
surgical appendectomy in most patients
-When possible, a laparoscopic approach is preferred to open laparotomy
(can diagnose with abd ultrasound or CT scan)
Prior to surgery, patients should be given _______
broad-spectrum antibiotics with gram-negative and anaerobic coverage to reduce the incidence of postoperative infections
Emergency appendectomy is required in patients with
perforated appendicitis with generalized peritonitis
Intestinal Tuberculosis
- common in underdeveloped countries
- US incidence has been rising in immigrant groups and patients with AIDS
- Active pulmonary disease is present in less than 50% of patients
- The most frequent site of involvement is the ileocecal region
Intestinal Tuberculosis is caused by
Mycobacterium tuberculosis and M bovis
S/S of Intestinal Tuberculosis
- May be without symptoms or complain of chronic abdominal pain, obstructive symptoms, weight loss, and diarrhea
- An abdominal mass may be palpable
- Complications include intestinal obstruction, hemorrhage, and fistula formation
With Intestinal Tuberculosis, the purified protein derivative (PPD) skin test may be
negative, especially in patients with weight loss or AIDS
During Int Tuberculosis, barium radiography may demonstrate ________ and abdominal CT may show __________
radiograph- mucosal ulcerations, thickening, or stricture formation
Abdominal CT may show thickening of the cecum and ileocecal valve and massive lymphadenopathy
During Int Tuberculosis, colonoscopy may demonstrate
an ulcerated mass, multiple ulcers with steep edges and adjacent small sessile polyps, small ulcers or erosions, or small diverticula, most commonly in the ileocecal region
The diagnosis if Int TB is established by either endoscopic or surgical biopsy revealing
acid-fast bacilli, caseating granuloma, or positive cultures from the organism
(biopsy and PCR is most sensitive)
Treatment for Int TB
Treatment with standard antituberculous regimens is effective
Protein-Losing Enterpathy
- A number of conditions that result in excessive loss of serum proteins into the gastrointestinal tract
- Proteins may be lost through one of three mechanisms:
1. Mucosal disease with ulceration
2. Lymphatic obstruction
3. Idiopathic change in permeability of mucosal capillaries and conductance of interstitium, resulting in “weeping” of protein-rich fluid from the mucosal surface
Lab findings with Protein-Losing Enterpathy
- Hypoalbuminemia and
- elevated fecal alpha-1-antitrypsin level
(Treatment is directed at the underlying cause)
In most cases, protein-losing enteropathy is recognized as a sequela of a known gastrointestinal disorder.
Protein-losing enteropathy must be distinguished from other causes of hypoalbuminemia.
It’s confirmed by determining the _______
gut alpha-1-antitrypsin clearance
What levels are useful to screen for autoimmune disorders?
Serum ANA and C3
Stool samples should be examined for
ova and parasites
Evidence of malabsorption is evaluated by
means of a stool qualitative fecal fat determination
