GI Ddx (Pass NPLEX) Flashcards
What is the difference between laparoscopy and laparotomy?
Laparoscopy uses several small incisions often called “keyhole” incisions, one at the belly button and approx. 2 or more elsewhere, depending on what needs to be done. Since the incisions are smaller, healing time is shorter as well as the hospital stay.
Laparotomy is the traditional open abdominal surgery. Incision can be 4 inches. This method has a much longer recovery (6 to 8 weeks).
Meckel’s Diverticulum may mimic the symptoms of what other condition?
Appendicitis.
Therefore during an appendectomy the ileum should be checked for the presence of Meckel’s diverticulum. If it is found to be present it should be removed along with the appendix.
What is the keynote symptom/sign of an ileus?
Abdominal distention
Why is a barium X Ray used in Crohn’s Disease?
A barium X-Ray can show where lesions are active in the small intestine that can’t easily be viewed
Why does Lactose Intolerance often occur with Celiac Disease?
Lactase is produced within the villi, therefore if the villi are damaged there will be insufficient lactase enzyme
What is a Volvulus?
Twisting of the intestines; often related to constipation or laxative abuse in adults
What is Curling’s ulceration of the duodenum?
Severe stress (such as burns or bodily injuries) that causes shock. The hypotension (from shock) then leads to decreased gastric mucosal blood supply and a resultant ischemic ulcer forms
What is the main investigation method for toxic megacolon?
Abdominal plain film repeated every 12-24 hours (because signs can fluctuate rapidly)
What is a common sequela to ileal resection in Crohn’s Disease?
Urolithiasis
What is Hirschsprung’s disease?
It is an autosomal dominant condition, in which the myenteric plexus does not develop. The affected segment of the colon fails to relax, causing an obstruction.
More common in boys than girls
Why are Meckel’s diverticulum occasionally involved in peptic ulceration?
Meckel’s Diverticulum often have ectopic gastric (or pancreatic) tissue. The gastric tissue may increase HCl production and thereby lead to ulceration.
Describe the Rule of 2s with respect to Meckel’s Diverticulum?
2% of population
2:1 male-to-female ratio
2% of cases are symptomatic
Found within 2 feet of the ileocecal valve
2 inches in length
2 ectopic types of tissue may be found (gastric or pancreatic)
present by age of 2
What is adynamic ileus? etiology?
GI obstruction from motor dysfunction (there is NO physical block present)
Usually occurs in reaction to abdo surgery, hypothyroidism, spinal cord injury
Are perianal skin tags more common in Crohn’s or Ulcerative Colitis?
Crohn’s disease (75% of cases
What part of the GI tract is typically spared in toxic megacolon?
The rectum
Crohn’s vs Ulcerative Colitis: Which condition is more likely to have fistula as a comorbidity?
Crohn’s Disease
a. ) Enterocutaneous (MC)
b. ) Enteroenteral
c. ) Enterovesicular (frequent UTIs)
d. ) Enterovaginal
Is uveitis more common in Crohn’s or Ulcerative Colitis?
Crohn’s Disease
Where is the most common location of diverticula?
In the sigmoid colon
What is Meckel’s Diverticulum?
Meckel’s Diverticulum is a small out-pouching in the small intestine. It is remnant of the embryonic viteline duct
Describe the pathophysiology behind Celiac Disease
Celiac disease is an auto-immune reaction that predispose a patient to an averse immunologic response in the presence of prolamines (high proline-containing proteins such as gliadin/gluten from wheat, rye, spelt, and barley).
Upon exposure to gliadin the enzyme tissue transglutaminase cross-links with gliadin/gluten that prompts a cross-reaction B-cell production of anti-tissue transglutaminase antibodies in individuals with variant HLA DQ2 & HLA DQ8. The antibodies then initiate an inflammatory cascade that leads to intestinal villous atrophy. The villous atrophy and truncation leads to a loss of surface area and gross nutrient malabsorption.
What diarrheal cause has an abrupt onset of profusely watery diarrhea without pain or nausea/vomiting?
Cholera
What bacterial food poisoning can inoculate in rice?
Bacillus cereus
How do you confirm a salmonellosis diagnosis?
A Rise in serum O and H agglutinin titers 3-4 weeks post-infection
Aside from diarrhea, what are the main symptoms of botulism?
- ) Bilateral descending flaccid paralysis
- ) Loss of Pupillary light reflex
- ) Double vision or blurred vision
- ) Eventual constipation
MC cause of traveler’s diarrhea?
Enterotoxigenic Echerichia coli (ETEC)
What is Hemolytic Uremic Syndrome?
A triad of:
- ) Hemolytic Anemia
- ) Thrombocytopenia
- ) Acute renal failure
Related to EHEC, Shigella, or Staphylococcus gastrointestinal infection
When do Sx of HUS start?
What are the symptoms of hemolytic uremic syndrome?
The symptoms develop about 5-10 days after the onset of EHEC (Shiga-like toxin) diarrhea:
- ) Thrombocytopenia (purpura, epistaxis, hemoptysis, GI bleeding)
- ) Microangiopathic hemolytic anemia (MAHA)
i. ) The endothelial layer of small vessels becomes damaged and results in fibrin deposition and platelet aggregation. Then as RBCs travel through the damaged blood vessels they are fragmented (into schistocytes) resulting in intravascular hemolysis. - ) Renal Failure (oliguria, hematuria)
What are the different types of E coli?
- ) Enterotoxigenic (ETEC) - produces enterotoxins and Traveller’s diarrhea. There is no inflammation or invasion
- ) Enteropathogenic (EPEC) - adheres to apical membrane and flattens villi resulting in decreased absorption. No toxin produced. Usually in children (P for pediatrics)
- ) Enteroinvasive (EIEC) - plasmid mediated invasiveness that is similar to shigella. It causes dysentery. Necrosis and inflammation are present.
- ) Enterohemorhagic (EHEC) - produces shiga-like toxin with dysentery and Hemolytic-uremic syndrome
What is the most common viral cause of diarrhea?
Rotavirus
What are the most concerning complications of botulism?
Aspiration pneumonia and respiratory failure
In staphylococcal food poisoning, how will an investigative stool culture and gram stain come back?
Both the stool culture and gram stain will be negative because the food poisoning is toxin-mediated not pathogen mediated
What is the most common bacterial cause of bloody diarrhea in USA?
Campylobacter jejuni
What parasitic infection produces respiratory complaints such as a cough, dyspnea, and pulmonary infiltrates from larval migration?
Ascaris lumbricoides (roundworm)
1.) What form of E.coli infectious diarrhea is accompanied by bloody diarrhea? 2.) What is the toxin found in this particular strain of E coli?
Enterohemorrhagic E.coli (EHEC) with Shiga-like toxin
Why is botulism a greater concern in infants?
Clostridium botulinum spores are able to colonize in the colon of infants, whereas in adults the botulism experienced is solely from preformed toxin
What parasitic infection is often associated with drinking water from streams while camping?
Giardia lamblia
How can you rule out Guillain-Barre Syndrome in the investigation of Botulism?
Electromyography
Which parasite is hallmarked by nocturnal rectal pruritis?
Enterobius vermicularis (pinworm)
What are the 4 most common viral causes of diarrhea?
Norwalk Virus Adenovirus Rotavirus Calci Virus Mnemonic: NARC
What food poisoning may present similarly to appendicitis?
Yersinia enterocolitica
Shigellosis vs Salmonellosis: Which requires a very small inoculum concentration?
Shigellosis requires a very small inoculum concentration (it is very contagious)
Salmonellosis requires a large inoculum concentration
What toxin is associated with hemolytic uremic syndrome?
Shiga toxin generally from EHEC and sometimes from Shigella or Campylobacter
What are the main signs and symptoms of typhoid fever?
- ) Rose spots on the abdomen
- ) Fever
- ) Headaches
- ) Diarrhea
What parasitic infection is identified using the scotch tape test?
Enterobius vermicularis because the pinworms lay eggs at night around the rectal sphincter
Hookworms (Necator americanus & Ancylostoma duodenale) may cause what extra-intestinal condition?
Anemia
What bacteria can cause Reactive Arthritis? What are the symptoms of reactive arthritis?
Salmonella, Shigella, Campylobacter, Chlamydia, Streptococcus (post-streptococcal reactive arthritis), Yersinia
Symptoms = Uveitis, Urethritis, Arthritis
Mnemonic: Can’t See, Can’t Pee, Can’t Climb a Tree
Hepatocellular carcinoma can stem from what condition?
Liver cirrhosis
What is the incubation period for Hepatitis A Virus?
30 days (average)
2-6 weeks
What are your main DDxs for hepatomegally?
1.) Congestive (Right) Heart Failure
- ) Infiltrative
i. ) Malignancy (leukemia, hepatocarcinoma)
ii. ) Benign (fatty liver, cysts, hemochromatosis, amyloidosis) - ) Proliferative
i. ) Infectious/Inflammatory (viral, TB, abcess, granulomas)
What are the 2 major complications associated with hereditary hemochromatosis?
- ) Liver cirrhosis
2. ) Pancreatic Failure resulting in diabetes
Caput medusae occurs in what condition?
Liver cirrhosis.
Caput medusae is the appearance of distended and engorged paraumbilical veins
What percent of patients with Hepatitis C develop cirrhosis or hepatocarcinoma?
20%
What do interferons do?
They interfere with viruses
IFN alpha + beta inhibit viral protein synthesis by inducing the production of ribonuclease which degrades the mRNA of the virus
IFN gamma increases MHC 1 and 2 expression
What is Primary Sclerosing Cholangitis?
The inflammation (cholangitis) and scarring (sclerosing) of the bile ducts either in the liver (intrahepatic) or extrahepatically.
The scarring impedes bile flow (cholestasis) and results in liver cirrhosis, liver cancer, and liver failure.
Hepatomegally is present at what stage of alcoholic hepatitis?
Early on. In later stages of hepatitis the liver shrinks.
- ) What does AST do?
2. ) Where is it found?
1.) Aspartate Transaminase catalyzes the interconversion of aspartate and a-ketoglutarate to oxaloacetate and glutamate.
Aspartate (Asp) + a-ketoglutarate ? oxaloacetate + glutamate (Glu)
2.) Found in cardiac tissue, liver, skeletal muscle, RBCs
What should the practitioner screen for in patients with unexplained NASH?
- ) Diabetes & Insulin Resistance
2. ) Hemochromatosis
What are the causes of biliary tract obstructions?
- ) Gall stones
- ) Cancer
- ) Hemobilia - occurs when there is a fistula between the splanchnic circulation and the hepatic biliary system
- ) Sclerosing cholangitis
What are the 3 major types of Jaundice?
- ) Hemolytic = the breakdown of red blood cells
- ) Hepatic = the excretion of bile is impaired due to dysfunctional hepatocytes
- ) Cholestatic = obstruction of the bile duct prevents the successful excretion of bile
What is Charcot’s triad?
- ) RUQ pain
- ) Fever
- ) Jaundice
The three most common symptoms in cholangitis (bacterial infection of gallbladder that requires emergency antibiotics and/or surgery)
What population group is at the greatest risk of hereditary hemochromatosis?
Celtic, British, and Sacndinavian people
What is the cause of primary sclerosing cholangitis?
It is thought to be autoimmune; more than 80% of cases occur in patients with ulcerative colitis.
What are the main risk factors associated with chronic pancreatitis?
- ) Alcoholism
- ) Hypercalcemia (rare)
- ) Pancreatic Cancer
- ) Cholelithiasis that is obstructing the pancreatic duct
H. Pylori infected gastritis most commonly affects what part of the stomach?
The antrum
Describe the difference between Type-A and Type-B Gastritis
Type-A Gastritis (causing pernicious anemia) = autoimmune antibodies against parietal cells leading to achlorhyrdia and a decrease in Intrinsic Factor
Type-B Gastritis (from H.pylori)
a.) Other causes = NSAIDs, alcohol, smoking, elderly, stress
What is Zollinger-Ellison Syndrome?
Triad of:
- ) Gastrinoma tumour in the pancreas or duodenum, causing:
- ) Gastric acid hypersecretion , causing:
- ) Severe peptic ulceration
If you have an esophageal condition resulting in dysphagia and iron deficiency, what is the most likely diagnosis?
Plummer-Vinson Syndrome that results in upper esophageal webs, iron deficiency, glossitis, and cheilosis
Esophageal webs are most commonly associated with what condition?
Plummer-Vinson Syndrome
Marked by: esophageal webs, iron deficiency, cheilosis/angular stomatitis (dry scaling lips), and glossitis. The condition typically occurs in middle-aged females
What are the 3 most common causes of Parotiditis?
- ) Mumps virus
- ) S.aureus (suppurative parotiditis)
- ) Sjorgren’s disease
Plummer-Vinson Syndrome increases the risk of what cancer?
Post-cricoid Cancer
What is Barrett’s Esophagus?
The metaplastic change of stratified squamous cells in the lower esophagus to columnar epithelia normally found in the lower GIT
This can result in esophageal stricture, ulceration, or cancer
Diverticulum in the oropharynx just above the cricopharyngeal muscle (above the upper esophageal sphincter) is called?
Zenker’s Diverticulum
If you have an esophageal condition resulting in dysphagia that is made worse by anxiety, what is the most likely diagnosis? How would you evaluate it?
Globus sensation
All evaluations will come back negative because there is no organic pathology.
What is Esophageal Atresia?
A congenital condition where the esophagus ends in a blind-ended pouch rather than connecting normally to the stomach. It often results in fistula with the trachea
What is Zenker’s Diverticulum?
It is a herniation/out-pouching of the esophagus generally at Killian’s trinagle (the point of least resistance) in the proximal posterior esophagus that occurs because of increased traction and pulsation mechanisms of the esophagus.
What are the main symptoms of Zenker’s Diverticulum?
- ) Dysphagia
a. ) < supine (b/c the diverticulum is posterior) - ) Regurgitation of food & halitosis
- ) Sometimes a cough (d/t aspiration)
- ) What is achalasia?
2. ) What are the complications?
- ) The loss of lower esophageal motility, causing an inability to relax the LES. This results in an enlarged esophageal lumen with chronic food stasis
- ) Complications = aspiration pneumonia and esophageal cancer
What would your management plan for Plummer-Vinson’s esophageal webs be?
Refer to a gastroenterologist
What is the difference between a true and false diverticulum?
True Diverticulum is the outpouching of the colon wall (typically located in the sigmoid) that contains all layers, including the muscularis and adventitial layers. True Diverticulum are congenital and typically occur on the right side.
False Diverticulum (Pseudodiverticulum) is the outpouching of the colon wall that only contains the mucosal and submucosal layers. It is acquired and typically increases in incidence with age (>40 yoa). Generally located on the left side
What are the main interventions for diverticulosis?
- ) High Fiber Diet
- ) Avoid Seeds/nuts
- ) Probiotics
- ) Castor Oil Packs & Avoid Constipation
a. ) Constipation increases colonic pressure and may worsen any herniated colonic tissue - ) Weight Loss & Exercise
What are the 4 degrees of Internal Hemorrhoids?
First Degree - no prolapse
Second Degree - prolapses during defecation but reduces spontaneously
Third Degree - prolapses and requires manual correction
Fourth Degree - Prolapses out of anus and is not reducible
What are the main risk factors for Toxic Megacolon?
Risk Factors:
i. ) IBD (Crohn’s & Ulcerative Colitis)
ii. ) Pseudomembranous colitis
iii. ) antimotility drug use
iv. ) HIV infection
What are the two shapes of colorectal polyps?
Sesile (flat) & Pedunculated (on a stalk)
Compare and contrast Tubular (Pedunculated) and Villous (Sessile) Polyps:
- ) Incidence rate
- ) Size
- ) Malignant Potential
- ) Distribution
- ) Tubular polyps are more common (60-80%) whereas villous polyps are less common (10%)
- ) Tubular polyps are small (<2cm) while Villous polyps are large (>2cm)
3.) Tubular polyps have a low malignancy potential. Villous polyps infer a high malignancy risk.
Note: the larger the polyp, the greater the cancer risk
4.) Villous polyps typically occur on the left side. Tubular polyps are evenly distributed
Rubber band ligation of hemorrhoids. Is it performed on internal or external hemorrhoids?
Internal hemorrhoids of any grade.
What part of the GI tract is typically spared in toxic megacolon?
The rectum.
