GI Diagnostics & Treatment 3 — Questions and Answers
Question 1: What is the recommended colonoscopy surveillance interval for a patient found to have 3 tubular adenomas (each <10 mm) on screening colonoscopy?
- 1 year
- 3 years (Correct answer)
- 5 years
- 10 years
Correct answer: 3 years
Per current guidelines, 3-4 small (<10 mm) tubular adenomas without high-grade dysplasia warrant repeat colonoscopy in 3 years.
Question 2: A patient with chronic hepatitis C genotype 1 is being treated with direct-acting antivirals. What defines a sustained virologic response (SVR)?
- Undetectable HCV RNA at end of treatment
- Undetectable HCV RNA 12 weeks after completing treatment (Correct answer)
- HCV RNA >2 log reduction from baseline at week 4
- Anti-HCV antibody negativity at 6 months
Correct answer: Undetectable HCV RNA 12 weeks after completing treatment
SVR12 (undetectable HCV RNA 12 weeks post-treatment) is considered a functional cure and is associated with dramatically reduced risk of cirrhosis and HCC.
Question 3: Which of the following endoscopic findings is most consistent with Barrett's esophagus?
- Pale, irregular Z-line at the GEJ
- Salmon-colored tongues of mucosa extending proximal to the GEJ (Correct answer)
- Friable, erythematous mucosa in the distal esophagus
- White plaques on the esophageal wall
Correct answer: Salmon-colored tongues of mucosa extending proximal to the GEJ
Barrett's esophagus appears as salmon-colored (reddish) columnar epithelium extending proximally from the gastroesophageal junction, confirmed by biopsy showing intestinal metaplasia.
Question 4: A 70-year-old patient on warfarin presents with hematemesis and hemodynamic instability. After resuscitation, what is the most appropriate next step?
- CT angiography of the abdomen
- Tagged red blood cell scan
- Emergent upper endoscopy (Correct answer)
- Nasogastric tube placement and observation
Correct answer: Emergent upper endoscopy
Emergent upper endoscopy within 24 hours (or sooner if hemodynamically unstable after resuscitation) is both diagnostic and therapeutic for upper GI bleeding.
Question 5: What is the primary mechanism by which rifaximin helps in the management of irritable bowel syndrome with diarrhea (IBS-D)?
- Reduces gut motility by binding to mu-opioid receptors
- Suppresses intestinal microbiota, reducing gas production and bloating (Correct answer)
- Inhibits chloride channels reducing intestinal secretion
- Blocks serotonin receptors in the gut
Correct answer: Suppresses intestinal microbiota, reducing gas production and bloating
Rifaximin, a non-absorbable antibiotic, modulates the gut microbiome, reducing gas-producing bacteria and improving bloating and diarrhea in IBS-D.
Question 6: A patient with alcoholic cirrhosis and new-onset ascites is started on spironolactone. What is the primary mechanism of this treatment?
- Blocks aldosterone receptors in the collecting duct, promoting sodium excretion (Correct answer)
- Inhibits aquaporin channels, reducing water reabsorption
- Directly reduces portal hypertension by splanchnic vasoconstriction
- Inhibits antidiuretic hormone release from the pituitary
Correct answer: Blocks aldosterone receptors in the collecting duct, promoting sodium excretion
Spironolactone is a mineralocorticoid antagonist that blocks aldosterone-mediated sodium retention, the primary driver of ascites formation in cirrhosis.
Question 7: Which of the following is the most sensitive test for diagnosing acute pancreatitis in the first 24 hours of symptom onset?
- Serum lipase (Correct answer)
- Serum amylase
- CT abdomen with contrast
- Urinary amylase
Correct answer: Serum lipase
Serum lipase is more sensitive and specific than amylase for acute pancreatitis and remains elevated longer (up to 14 days vs 3-5 days for amylase).
GI Diagnostics & Treatment 3
What is the recommended colonoscopy surveillance interval for a patient found to have 3 tubular adenomas (each <10 mm) on screening colonoscopy?