Gastroenterology and Hepatology Flashcards

A 58-year-old man with alcoholic cirrhosis develops confusion and asterixis. Ammonia level is elevated. Which treatment is most appropriate?

Answer: Lactulose

Lactulose is first-line therapy for hepatic encephalopathy, reducing ammonia absorption by acidifying colonic contents and promoting excretion.

A 45-year-old woman presents with jaundice, pruritus, and elevated alkaline phosphatase. AMA is positive. What is the most likely diagnosis?

Answer: Primary biliary cholangitis

Anti-mitochondrial antibody (AMA) positivity with cholestatic pattern strongly suggests primary biliary cholangitis, a chronic autoimmune bile duct disease predominantly affecting middle-aged women.

A patient with long-standing Crohn's disease develops right lower quadrant pain and fever. CT shows a 4 cm fluid collection adjacent to the terminal ileum. What is the best next step?

Answer: Percutaneous drainage plus antibiotics

A walled-off abscess in Crohn's disease is best managed with percutaneous drainage plus antibiotics, avoiding emergent surgery and allowing inflammation to subside before elective resection if needed.

Which of the following is the most common cause of acute pancreatitis in the United States?

Answer: Gallstones

Gallstones (biliary pancreatitis) account for approximately 40% of acute pancreatitis cases in the US, making it the most common etiology.

A 62-year-old man undergoes colonoscopy showing a 1.5 cm sessile serrated lesion in the ascending colon. When should surveillance colonoscopy be performed?

Answer: 3 years

Sessile serrated lesions ≥10 mm or with dysplasia warrant 3-year surveillance colonoscopy per current ACG guidelines due to their malignant potential.

A 35-year-old woman with diarrhea, bloating, and weight loss has anti-tissue transglutaminase IgA antibodies. Duodenal biopsy shows villous atrophy and crypt hyperplasia. What is the first-line treatment?

Answer: Gluten-free diet

Celiac disease is treated with strict adherence to a gluten-free diet, which leads to mucosal healing and resolution of symptoms in the majority of patients.

A patient with cirrhosis develops spontaneous bacterial peritonitis (SBP). After treatment, which prophylactic antibiotic is recommended to prevent recurrence?

Answer: Norfloxacin

Norfloxacin (or trimethoprim-sulfamethoxazole as an alternative) is recommended for long-term secondary prophylaxis after a first episode of SBP to reduce recurrence risk.

A 70-year-old man presents with dysphagia to solids progressively worsening over 3 months with a 15-pound weight loss. What is the most appropriate initial evaluation?

Answer: Upper endoscopy

Upper endoscopy (EGD) is the preferred initial test for progressive dysphagia with alarm features because it allows direct visualization and biopsy to evaluate for malignancy.

A 55-year-old woman with obesity and type 2 diabetes has AST 78 and ALT 92. Ultrasound shows echogenic liver. Which histologic finding distinguishes NASH from simple steatosis?

Answer: Lobular inflammation and hepatocyte ballooning

NASH is distinguished from simple steatosis by the presence of lobular inflammation and hepatocyte ballooning injury, which drive fibrosis progression and risk of cirrhosis.

A 28-year-old man has recurrent episodes of jaundice after fasting and during illness. All liver enzymes are normal except indirect bilirubin of 3.5 mg/dL. What is the most likely diagnosis?

Answer: Gilbert syndrome

Gilbert syndrome presents with isolated unconjugated hyperbilirubinemia triggered by fasting, stress, or illness, with otherwise normal liver function and benign prognosis.

A 50-year-old man with known esophageal varices presents with hematemesis. He is hemodynamically stable after resuscitation. What is the most appropriate endoscopic treatment?

Answer: Band ligation

Endoscopic variceal band ligation (EVL) is the preferred endoscopic treatment for acute esophageal variceal bleeding due to its superior efficacy and lower complication rate compared to sclerotherapy.

Which of the following best describes the mechanism of action of ursodeoxycholic acid (UDCA) in primary biliary cholangitis?

Answer: Displacement of toxic bile acids and hepatoprotection

UDCA works by replacing toxic hydrophobic bile acids, stimulating bile secretion, and providing cytoprotection to cholangiocytes, slowing disease progression in PBC.

A 40-year-old woman has chronic diarrhea, flushing, and wheezing. Urinary 5-HIAA is markedly elevated. Which imaging study is most appropriate to localize the primary tumor?

Answer: Octreotide scan (somatostatin receptor scintigraphy)

Somatostatin receptor scintigraphy (octreotide scan or Ga-68 DOTATATE PET/CT) is the preferred functional imaging modality to localize carcinoid tumors expressing somatostatin receptors.

A patient is found to have H. pylori infection on urea breath test after completing a PPI plus clarithromycin-based triple therapy. What is the best next step?

Answer: Bismuth quadruple therapy

After failure of clarithromycin-based triple therapy, bismuth quadruple therapy (PPI + bismuth + tetracycline + metronidazole) is recommended as salvage treatment.

A 55-year-old man with no prior GI history has a positive fecal immunochemical test (FIT). What is the most appropriate next step?

Answer: Colonoscopy

A positive FIT requires diagnostic colonoscopy to evaluate for colorectal cancer or adenomatous polyps; no alternative testing is appropriate after a positive non-invasive screen.

A 60-year-old with known achalasia undergoes esophageal manometry showing aperistalsis and incomplete lower esophageal sphincter relaxation. Which treatment has the lowest risk of GERD as a complication?

Answer: Heller myotomy with fundoplication

Heller myotomy combined with partial fundoplication (Dor or Toupet) reduces post-procedural GERD compared to myotomy alone or POEM, which disrupts the anti-reflux barrier without fundoplication.

A 38-year-old with Crohn's disease on azathioprine develops a perianal fistula that fails to close with antibiotics. What biologic therapy is FDA-approved for fistulizing Crohn's disease?

Answer: Infliximab

Infliximab is the only biologic with FDA approval specifically for fistulizing Crohn's disease, demonstrated in the landmark ACCENT II trial to induce and maintain fistula closure.

A patient with severe acute pancreatitis is being managed in the ICU. CT shows 40% pancreatic necrosis without infection. When should nutritional support be initiated?

Answer: Early enteral nutrition via nasojejunal tube within 24-48 hours

Early enteral nutrition via nasojejunal (or nasogastric) tube within 24-48 hours is preferred in severe pancreatitis to maintain gut barrier function and reduce infectious complications compared to TPN.

A 72-year-old woman presents with acute onset of bright red blood per rectum, crampy left lower quadrant pain, and tenesmus without systemic symptoms. CT shows segmental colonic wall thickening at the splenic flexure. What is the most likely diagnosis?

Answer: Ischemic colitis

Ischemic colitis classically affects watershed areas like the splenic flexure in older patients and presents with acute crampy pain and bloody diarrhea; segmental distribution on CT is characteristic.

A 45-year-old man with hepatitis B (HBsAg positive, HBeAg positive, HBV DNA 8 log IU/mL, ALT 180) has liver biopsy showing moderate inflammation and bridging fibrosis. Which treatment is most appropriate?

Answer: Tenofovir disoproxil fumarate

Tenofovir (TDF or TAF) is the preferred first-line treatment for chronic hepatitis B with significant disease activity and fibrosis due to its potency, high barrier to resistance, and safety profile.