MD Gastrointestinal Tract Disorders 2

Question 1

A 45-year-old man presents with episodic epigastric pain relieved by food and antacids. Upper endoscopy reveals a duodenal ulcer. Which organism is most likely responsible?

Accepted Answer

Helicobacter pylori

Answer

Helicobacter pylori is responsible for approximately 90% of duodenal ulcers and disrupts the mucosal defense by producing urease and inflammatory mediators.

Question 2

A patient with ulcerative colitis limited to the rectum is best described as having which subtype?

Accepted Answer

Proctitis

Answer

Proctitis refers to ulcerative colitis confined to the rectum, the most distal and mildest form of the disease.

Question 3

A 60-year-old woman presents with progressive dysphagia to solids then liquids, weight loss, and regurgitation of undigested food. Barium swallow shows a 'bird's beak' tapering. What is the diagnosis?

Accepted Answer

Achalasia

Answer

Achalasia is characterized by failure of the lower esophageal sphincter to relax and loss of peristalsis, producing the classic bird's beak appearance on barium swallow.

Question 4

Which complication is most feared in a patient with Barrett's esophagus?

Accepted Answer

Adenocarcinoma of the esophagus

Answer

Barrett's esophagus involves intestinal metaplasia of the lower esophageal epithelium and is a precursor to esophageal adenocarcinoma.

Question 5

A newborn fails to pass meconium within 48 hours of birth. Rectal biopsy shows absence of ganglion cells in the submucosal and myenteric plexuses. What is the diagnosis?

Accepted Answer

Hirschsprung disease

Answer

Hirschsprung disease is caused by failure of neural crest cell migration, resulting in an aganglionic segment of colon that cannot relax.

MD - Doctor of Medicine Practice Test

MD - Doctor of Medicine Practice Test

MD Gastrointestinal Tract Disorders 2