PANCE Gastrointestinal 4 — Questions and Answers
Question 1: A 45-year-old obese woman presents with episodic RUQ pain after eating, with ultrasound showing gallstones but no wall thickening or pericholecystic fluid. What is the diagnosis?
- Acute cholecystitis
- Biliary colic (Correct answer)
- Choledocholithiasis
- Cholangitis
Correct answer: Biliary colic
Biliary colic presents with episodic RUQ pain triggered by fatty meals, but unlike acute cholecystitis, there is no fever, prolonged pain, or sonographic signs of inflammation.
Question 2: A patient with chronic alcohol use presents with hematemesis. Upper endoscopy reveals tortuous, dilated veins at the gastroesophageal junction. What is the mechanism of this finding?
- Increased portal venous pressure causing portosystemic shunting (Correct answer)
- Direct erosion of the mucosa by alcohol
- Coagulopathy from liver disease
- Aortoenteric fistula
Correct answer: Increased portal venous pressure causing portosystemic shunting
Esophageal varices develop when portal hypertension causes blood to shunt through portosystemic collaterals including the submucosal esophageal veins.
Question 3: Which of the following best distinguishes Crohn disease from ulcerative colitis on endoscopy?
- Presence of pseudopolyps
- Continuous mucosal involvement from the rectum
- Skip lesions with cobblestone appearance (Correct answer)
- Involvement limited to the colon
Correct answer: Skip lesions with cobblestone appearance
Crohn disease classically shows discontinuous skip lesions, transmural inflammation, and cobblestone mucosa due to deep fissuring ulcers, unlike UC's continuous mucosal disease.
Question 4: A 70-year-old presents with sudden onset severe abdominal pain out of proportion to exam, with a history of atrial fibrillation. Lactate is elevated. What is the most likely diagnosis?
- Ischemic colitis
- Acute mesenteric ischemia (Correct answer)
- Perforated peptic ulcer
- Acute pancreatitis
Correct answer: Acute mesenteric ischemia
Acute mesenteric ischemia from embolism (commonly from atrial fibrillation) causes severe pain disproportionate to exam findings with elevated lactate from bowel ischemia.
Question 5: Which of the following is the recommended screening interval for colonoscopy in an average-risk patient with no findings on initial screening at age 50?
- 3 years
- 5 years
- 10 years (Correct answer)
- 15 years
Correct answer: 10 years
Current guidelines recommend repeat colonoscopy in 10 years for average-risk patients with a normal (no polyps) initial screening colonoscopy.
Question 6: A 25-year-old presents with recurrent abdominal pain, diarrhea, and mouth sores. Labs show elevated ESR and CRP. Colonoscopy shows ileitis with skip lesions. What extraintestinal manifestation is most commonly associated with this condition?
- Pyoderma gangrenosum
- Primary sclerosing cholangitis
- Erythema nodosum (Correct answer)
- Ankylosing spondylitis
Correct answer: Erythema nodosum
Erythema nodosum (tender red nodules on the shins) is the most common extraintestinal skin manifestation of both Crohn disease and ulcerative colitis.
Question 7: Which test is most appropriate for diagnosing Clostridioides difficile infection?
- Stool culture for C. difficile
- PCR for C. difficile toxin genes (Correct answer)
- Colonoscopy showing pseudomembranes
- Stool Gram stain
Correct answer: PCR for C. difficile toxin genes
Nucleic acid amplification tests (NAAT/PCR) for C. difficile toxin genes are the most sensitive and specific initial diagnostic test for C. diff infection.
PANCE Gastrointestinal 4
A 45-year-old obese woman presents with episodic RUQ pain after eating, with ultrasound showing gallstones but no wall thickening or pericholecystic fluid.
What is the diagnosis?