31 July 2026 – Gastrointestinal Question Bank

#1. A 55-year-old man with cirrhosis and known ascites presents with fever and diffuse abdominal pain. Diagnostic paracentesis is performed. Which finding on ascitic fluid analysis is diagnostic of spontaneous bacterial peritonitis?

Polymorphonuclear (PMN) cell count greater than 250 cells/mm3

Ascitic glucose less than 50 mg/dL

Total WBC count greater than 10;000/mm3

Ascitic protein greater than 3 g/dL

#2. A 65-year-old man presents with fever; jaundice; and RUQ pain that has progressed over the past two days. On exam; he is febrile; tachycardic; and scleral icterus is noted; with tenderness to palpation in the RUQ. Labs show elevated total and direct bilirubin; alkaline phosphatase; and leukocytosis. This clinical triad most strongly suggests which diagnosis?

Acute cholecystitis

Uncomplicated biliary colic

Ascending cholangitis

Simple cholelithiasis

#3. A 63-year-old woman with known cirrhosis is brought in by family for confusion and altered behavior over the past two days. On exam she has a flapping tremor when asked to extend her wrists. Ammonia level is elevated. What is the most appropriate first-line treatment?

Rifaximin as sole initial therapy

Lactulose

Strict long-term protein restriction

Neomycin as first-line therapy

#4. A 17-year-old boy undergoes colonoscopy after his father was diagnosed with colon cancer at age 35. The colonoscopy reveals thousands of adenomatous polyps carpeting the colon; and genetic testing confirms a germline APC gene mutation. What is the most appropriate management?

Chemotherapy without surgery

No intervention is needed at this age

Prophylactic colectomy

Surveillance colonoscopy alone; without surgery

#5. A 38-year-old woman is diagnosed with right-sided colon cancer. Her family history is notable for her mother having endometrial cancer at age 45 and her uncle having colon cancer at age 40. Genetic testing reveals a mismatch repair gene mutation. At what age should colonoscopy screening begin in affected family members?

In their 20s; with more frequent colonoscopy

Screening is not indicated

Age 50; as in the general population

Only after symptoms develop

#6. An 80-year-old woman with a recent hospitalization for hypotension due to sepsis now presents with crampy left-sided abdominal pain and bloody diarrhea. Colonoscopy shows mucosal ischemia most prominent at a particular anatomic watershed area. Which region is most vulnerable?

Splenic flexure

Duodenum

Cecum

Rectum

#7. A 48-year-old man with a history of heavy alcohol use presents after an episode of forceful; repeated vomiting following a night of binge drinking. He now has severe; tearing retrosternal chest pain radiating to the back; and on examination there is crepitus palpable over the chest wall and neck. Vital signs show tachycardia and hypotension. What is the most appropriate next diagnostic step?

Esophagram with water-soluble contrast

Upper endoscopy

CT chest without contrast

Chest X-ray alone; no further imaging needed

#8. A 24-year-old man presents with chronic abdominal pain; non-bloody diarrhea; and a perianal fistula. Colonoscopy shows patchy areas of inflammation separated by normal-appearing mucosa (“skip lesions”); with a cobblestone appearance; and biopsy shows transmural inflammation with non-caseating granulomas. Which antibody is most associated with this disease?

Anti-centromere antibody

Anti-mitochondrial antibody

ASCA (anti-Saccharomyces cerevisiae antibody)

p-ANCA

#9. A 35-year-old man with a history of heavy alcohol use presents with several episodes of forceful retching and vomiting after a night of drinking; followed by bright red hematemesis. He is hemodynamically stable; and abdominal exam is unremarkable. Upper endoscopy is planned. What is the most likely underlying lesion causing his bleeding?

A bleeding gastric ulcer

Rupture of distal esophageal varices

A longitudinal mucosal tear at the gastroesophageal junction

Full-thickness rupture of the esophageal wall

#10. A 52-year-old man presents with episodic; severe substernal chest pain that mimics angina; sometimes triggered by hot or cold liquids; along with intermittent dysphagia to both solids and liquids. Cardiac workup; including troponins and stress testing; is unremarkable. Esophageal manometry shows normal LES relaxation but multiple simultaneous; high-amplitude; uncoordinated contractions. What would barium swallow most likely demonstrate?

Rat tail sign

Apple core lesion

Corkscrew esophagus

Bird’s beak tapering

#11. A 60-year-old woman is admitted with acute pancreatitis. On admission; her labs are notable for mild leukocytosis and elevated lipase. Forty-eight hours later; her hematocrit has dropped by more than 10 points despite adequate fluid resuscitation; and her BUN has risen. Which of the following best reflects a poor prognostic indicator in this timeframe?

Elevated amylase level on admission

Elevated total bilirubin

Elevated lipase level on admission

Hematocrit drop of more than 10% within 48 hours

#12. A 48-year-old man presents with fatigue; new-onset diabetes; bronze-colored skin pigmentation; and joint pain in his second and third metacarpophalangeal joints. Echocardiogram shows early signs of restrictive cardiomyopathy. Labs reveal markedly elevated ferritin and transferrin saturation. Which genetic defect underlies this condition?

HFE gene mutation

Alpha-1 antitrypsin gene mutation

ATP7B gene mutation

SERPINA1 promoter mutation

#13. A 19-year-old presents with a 6-month history of worsening tremor; dysarthria; and personality changes; along with mild jaundice. Slit-lamp examination reveals golden-brown rings at the periphery of the cornea. Which laboratory finding would most support the diagnosis?

Elevated serum ferritin

Decreased serum ceruloplasmin with increased 24-hour urinary copper

Elevated serum ceruloplasmin

Elevated alpha-1 antitrypsin level

#14. A 61-year-old man presents with episodic facial flushing; watery diarrhea; and wheezing. Echocardiogram reveals tricuspid regurgitation and pulmonic stenosis. Imaging reveals a small bowel tumor with extensive liver metastases; and urinary 5-HIAA is markedly elevated. Under which circumstance do these systemic symptoms typically occur?

Only with tumors of pancreatic origin

When liver metastases bypass hepatic first-pass metabolism

With isolated lymph node involvement only

With a localized bowel tumor and no metastases

#15. A patient is started on omeprazole for symptomatic GERD. Which of the following best describes its mechanism of action?

Reversible blockade of histamine H2 receptors

Acts as a prostaglandin E1 analog

Blockade of muscarinic receptors on parietal cells

Irreversible inhibition of the H+/K+ ATPase in gastric parietal cells

#16. A 29-year-old woman presents with several months of bloody diarrhea and tenesmus. Colonoscopy shows continuous mucosal inflammation beginning at the rectum and extending proximally; with friable mucosa and pseudopolyps; without skip lesions. Which antibody is most commonly associated with this condition?

ASCA

p-ANCA

Anti-Smith antibody

Anti-double-stranded DNA

#17. A 27-year-old woman presents with chronic diarrhea; bloating; and unintentional weight loss. She also has an intensely itchy; blistering rash on her elbows and knees. Labs show iron-deficiency anemia. Which serologic test would best confirm the suspected diagnosis?

Anti-tissue transglutaminase IgA antibody

Anti-gliadin IgG antibody

Anti-mitochondrial antibody

Antinuclear antibody

#18. A 38-year-old man is diagnosed with a duodenal ulcer; and biopsy confirms Helicobacter pylori infection with no history of prior macrolide exposure. Which of the following is the most appropriate first-line treatment regimen?

Bismuth subsalicylate alone

PPI plus amoxicillin plus clarithromycin for 14 days

Metronidazole alone

PPI monotherapy for 8 weeks

#19. A 60-year-old man with known cirrhosis presents with large-volume hematemesis and is hemodynamically unstable. While preparations are made for urgent upper endoscopy; which of the following should be started immediately as first-line pharmacologic therapy?

Vasopressin

PPI alone

Octreotide infusion

Beta-blocker

#20. A 52-year-old man with a 20-year history of heavy alcohol use presents with recurrent episodes of dull epigastric pain; greasy foul-smelling stools; and new-onset diabetes. Abdominal CT shows diffuse pancreatic calcifications and ductal dilation. Given his malabsorption; which class of vitamins is he most at risk of deficiency in?

Vitamin B12 only

Water-soluble vitamins

Folate only

Fat-soluble vitamins (A; D; E; K)

#21. A 44-year-old man presents with a several-month history of gnawing epigastric pain that is relieved by eating but recurs 2-3 hours after meals and often wakes him at night. He denies NSAID use; alcohol; or smoking. Physical exam shows mild epigastric tenderness without rebound. Endoscopy reveals a clean-based duodenal ulcer. Which of the following is the most likely underlying cause?

Zollinger-Ellison syndrome

NSAID-induced mucosal injury

Helicobacter pylori infection

CMV infection

#22. A 55-year-old woman presents with several months of fatigue and generalized pruritus that is worse at night. Labs reveal a markedly elevated alkaline phosphatase with only mildly elevated transaminases; and antimitochondrial antibody testing is positive. What is the most likely diagnosis?

Wilson disease

Autoimmune hepatitis

Primary sclerosing cholangitis

Primary biliary cholangitis

#23. A 47-year-old woman presents with constant RUQ pain for the past 18 hours; associated with fever; nausea; and vomiting. On exam; she has inspiratory arrest during deep RUQ palpation. Labs show leukocytosis with a left shift. What is the most appropriate initial imaging study?

CT abdomen with contrast

HIDA scan as the first study

MRCP as the first study

Right upper quadrant ultrasound

#24. A 42-year-old obese woman with four children presents with recurrent episodes of postprandial RUQ pain after fatty meals; each lasting 1-2 hours and resolving spontaneously. Which classic risk factor profile best describes her presentation?

Female; Fat; Forty; Fertile

Young and athletic

Strict vegan diet

Male; thin; elderly

#25. The patient above is started on IV fluids and broad-spectrum antibiotics but remains febrile and hemodynamically borderline several hours later; with worsening bilirubin. What is the most appropriate next step in management?

Obtain MRCP only; with no intervention

Schedule elective outpatient cholecystectomy

Continue observation on antibiotics alone

Urgent ERCP for biliary decompression

#26. A 66-year-old man presents with 2 days of left lower quadrant pain; low-grade fever; and mild nausea. Exam reveals localized LLQ tenderness without peritoneal signs. Labs show leukocytosis. What is the most appropriate initial imaging study?

Barium enema

Colonoscopy performed immediately

Plain abdominal X-ray alone

CT abdomen/pelvis with contrast

#27. A 70-year-old woman develops profuse watery diarrhea and abdominal cramping one week after completing a course of clindamycin for a dental infection. Colonoscopy reveals yellow-white plaques adherent to the colonic mucosa. What is the most appropriate first-line treatment?

Oral vancomycin or fidaxomicin

Metronidazole

Ciprofloxacin

Intravenous vancomycin

#28. A 34-year-old nonsmoker presents with progressive dyspnea; and chest CT reveals panacinar emphysema most pronounced in the lung bases. Liver function tests are also abnormal; and liver biopsy shows PAS-positive; diastase-resistant globules within hepatocytes. What is the mechanism of the liver damage in this condition?

Accumulation of misfolded protein within hepatocytes

Copper deposition within hepatocytes

Autoimmune-mediated hepatocyte destruction

Iron deposition within hepatocytes

#29. A 58-year-old man with cirrhosis due to chronic alcohol use undergoes screening upper endoscopy; which reveals medium-sized esophageal varices without any stigmata of recent bleeding. He has never had a prior variceal bleed. Which of the following is the most appropriate measure to reduce his risk of a first bleeding episode?

Daily aspirin

Non-selective beta-blocker such as propranolol

PPI therapy alone

Daily octreotide

#30. A 50-year-old woman presents with recurrent; treatment-refractory peptic ulcers despite adequate PPI therapy; along with chronic watery diarrhea and unintentional weight loss. Endoscopy shows multiple ulcers in atypical locations; including the distal duodenum and jejunum. Fasting serum gastrin is markedly elevated even after stopping her PPI. Which test would best confirm the diagnosis?

Urea breath test

Secretin stimulation test

Somatostatin receptor scintigraphy alone

Repeat upper endoscopy alone

#31. Among patients with inflammatory bowel disease who develop primary sclerosing cholangitis; which subtype of IBD is more strongly associated with this hepatobiliary complication?

Both are equally associated

Ulcerative colitis

Crohn’s disease

Neither is associated

#32. A 58-year-old man presents with several months of migratory arthralgias; chronic diarrhea; weight loss; and progressive memory difficulties. Small bowel biopsy shows PAS-positive foamy macrophages infiltrating the lamina propria. What is the causative organism?

Giardia lamblia

Clostridioides difficile

Helicobacter pylori

Tropheryma whipplei

#33. A 22-year-old non-pregnant woman presents with periumbilical pain that has migrated to the right lower quadrant over the past 12 hours; accompanied by anorexia; nausea; and low-grade fever. Exam reveals tenderness at McBurney’s point with guarding. What is the most appropriate next step?

Ultrasound as the only imaging study

CT abdomen/pelvis

Immediate laparotomy without imaging

Barium enema

#34. A 30-year-old man with a known history of ulcerative colitis presents with progressive fatigue and pruritus over several months. Labs show a cholestatic pattern with markedly elevated alkaline phosphatase. MRCP reveals multifocal strictures alternating with dilated segments of the intrahepatic and extrahepatic bile ducts; giving a “beaded” appearance. This condition carries an increased risk of which malignancy?

Cholangiocarcinoma

Gastric cancer

Pancreatic cancer only

Hepatocellular carcinoma

#35. A 55-year-old man presents with a 10-year history of retrosternal burning pain that worsens when lying flat and after large meals; partially relieved by antacids. He denies dysphagia or weight loss. Upper endoscopy reveals salmon-colored; velvety mucosa extending 3 cm into the distal esophagus; replacing the normal pale squamous lining. Which of the following is the most appropriate next step?

Obtain esophageal biopsies of the abnormal mucosa

Start high-dose PPI and reassess symptoms in 6 weeks

Perform a barium swallow study

Test for Helicobacter pylori

#36. A 34-year-old woman with a known history of polycythemia vera presents with the subacute onset of abdominal pain; ascites; and tender hepatomegaly. Doppler ultrasound reveals thrombosis of the hepatic veins. Which underlying condition is most strongly associated with this presentation?

Chronic alcohol use

A hypercoagulable state

Chronic iron overload

Chronic viral hepatitis

#37. A healthy 25-year-old presents for a routine pre-employment screen. Serology shows HBsAg negative; anti-HBs positive; and anti-HBc negative. He reports having completed the hepatitis B vaccine series in childhood and denies any history of jaundice or liver disease. What does this serologic pattern most likely represent?

The “window period” of infection

Immunity from vaccination

Chronic hepatitis B infection

Acute hepatitis B infection

#38. A 45-year-old man presents with severe; constant epigastric pain radiating to the back; associated with nausea and vomiting. He denies alcohol use but reports recent episodes of colicky RUQ pain after fatty meals. Labs show lipase three times the upper limit of normal; and RUQ ultrasound reveals gallbladder stones without wall thickening. What is the most common overall cause of acute pancreatitis in the general population?

Alcohol use

Post-ERCP complication

Gallstones

Hypertriglyceridemia

#39. A 40-year-old woman reports 8 months of progressive difficulty swallowing both solids and liquids; along with regurgitation of undigested food and a 6-kg weight loss. She sometimes wakes at night coughing from aspirated food. Esophageal manometry shows elevated lower esophageal sphincter (LES) pressure that fails to relax with swallowing; and absent peristalsis in the esophageal body. A barium esophagram would most likely show which finding?

A “bird’s beak” tapering at the LES

A “corkscrew” pattern of contractions

An “apple core” lesion in the distal esophagus

A “string sign” in the terminal ileum

#40. A 28-year-old man presents with fatigue; low-grade fever; and jaundice for the past week. Labs show HBsAg positive; IgM anti-HBc positive; and HBeAg positive; with markedly elevated transaminases. What does this serologic pattern indicate?

Resolved hepatitis B infection

Chronic hepatitis B with low infectivity

Vaccinated; non-infected state

Acute hepatitis B with high infectivity