MD Gastrointestinal Tract Disorders 5 — Questions and Answers
Question 1: A 50-year-old man with a history of NSAID use presents with sudden onset epigastric pain radiating to the back and a rigid abdomen. Upright chest X-ray shows free air under the diaphragm. What has occurred?
- Acute mesenteric ischemia
- Perforated peptic ulcer (Correct answer)
- Acute pancreatitis
- Sigmoid volvulus
Correct answer: Perforated peptic ulcer
Perforated peptic ulcer causes pneumoperitoneum (free air under the diaphragm) and peritonitis, presenting as a surgical emergency with sudden severe epigastric pain and abdominal rigidity.
Question 2: A 2-year-old boy presents with colicky abdominal pain, vomiting, and currant jelly stools. Ultrasound shows a 'target sign' in the right upper quadrant. What is the diagnosis?
- Meckel's diverticulum
- Hirschsprung disease
- Intussusception (Correct answer)
- Malrotation with volvulus
Correct answer: Intussusception
Intussusception is the telescoping of one segment of bowel into another, classically presenting in children aged 6 months to 2 years with the triad of colicky pain, vomiting, and currant jelly stools.
Question 3: A patient presents with severe mid-epigastric pain radiating to the back, nausea, and vomiting after a heavy meal. Serum lipase is 1,200 U/L. Which is the most common cause of this presentation?
- Gallstones and alcohol use (Correct answer)
- NSAID use and hypercalcemia
- Hypertriglyceridemia and trauma
- Medications and autoimmune disease
Correct answer: Gallstones and alcohol use
Gallstones and alcohol use together account for approximately 80% of acute pancreatitis cases, with gallstones being the single most common cause in the US.
Question 4: A patient with long-standing Crohn's disease develops a fistula between the small bowel and bladder (enterovesical fistula). Which symptom would most specifically suggest this complication?
- Recurrent urinary tract infections with polymicrobial bacteria (Correct answer)
- Hematuria
- Dysuria without infection
- Urinary frequency and urgency
Correct answer: Recurrent urinary tract infections with polymicrobial bacteria
Enterovesical fistula allows intestinal bacteria to enter the bladder, causing recurrent polymicrobial urinary tract infections and pneumaturia (air in the urine).
Question 5: A 60-year-old man presents with difficulty swallowing, regurgitation of food eaten hours earlier, and a gurgling mass in the neck. Barium swallow shows a posterior pharyngeal outpouching. What is the diagnosis?
- Achalasia
- Esophageal web
- Zenker's diverticulum (Correct answer)
- Diffuse esophageal spasm
Correct answer: Zenker's diverticulum
Zenker's diverticulum is a false diverticulum (pulsion type) at Killian's triangle in the posterior hypopharynx, causing regurgitation of undigested food and a palpable neck mass.
Question 6: A 35-year-old woman with primary sclerosing cholangitis (PSC) is found to have concurrent inflammatory bowel disease. Which IBD pattern is most classically associated with PSC?
- Crohn's disease with perianal involvement
- Ulcerative colitis with backwash ileitis (Correct answer)
- Microscopic colitis
- Ischemic colitis
Correct answer: Ulcerative colitis with backwash ileitis
Primary sclerosing cholangitis is most strongly associated with ulcerative colitis, particularly pancolitis with backwash ileitis, occurring in up to 90% of PSC patients who have IBD.
Question 7: A 72-year-old man presents with acute onset severe abdominal pain out of proportion to physical findings, nausea, and bloody diarrhea. He has a history of atrial fibrillation. CT angiography confirms mesenteric ischemia. Which vessel is most commonly involved?
- Inferior mesenteric artery
- Superior mesenteric artery (Correct answer)
- Celiac artery
- Inferior mesenteric vein
Correct answer: Superior mesenteric artery
Acute mesenteric ischemia most commonly results from embolic occlusion of the superior mesenteric artery (SMA), which supplies the small intestine and proximal colon.
MD Gastrointestinal Tract Disorders 5
A 50-year-old man with a history of NSAID use presents with sudden onset epigastric pain radiating to the back and a rigid abdomen.
Upright chest X-ray shows free air under the diaphragm.
What has occurred?