A 75-year-old man presents two days after having sudden onset of abdominal pain in his left lower quadrant, which lasted for one day and was associated with the passage of several episodes of bloody stool. His pain has now resolved. He had a similar episode one month previously. His past medical history is notable for hypertension, diabetes mellitus, atrial fibrillation, and previous coronary artery bypass surgery. His medications include a $\beta$-blocker, metformin, and digoxin. His last screening colonoscopy four years ago was unremarkable. His abdominal exam is notable for mild tenderness in his left lower quadrant but is otherwise unremarkable. His cardiovascular exam is notable for an irregular heart rhythm with a normal ventricular rate. His labs reveal mild anemia, mildly elevated glucose levels, a normal white count and lactate levels and his abdominal x-ray is unremarkable. Which of the following statements are incorrect?

Correct Answer: B

Rationale: Colonic ischemia is the most likely diagnosis. Although diverticulitis and inflammatory bowel disease are possible, the short history is against IBD and to a lesser extent diverticulitis because the symptoms resolved without antibiotics. Colonic ischemia can present with mild transient symptoms that resolve without evidence on colonoscopy or persist with segmental hemorrhagic colitis, bleeding into the submucosa, gangrene, and eventually structuring. In addition to the causes listed in Answer C, other well-recognized causes of colonic ischemia include emboli, hypotension, vasculitis, hypercoagulable states, vascular surgery, and other drugs such as cocaine.

Correct Answer: D

Rationale: The allocation of cadaveric liver organs is based on severity of liver disease (model for end stage liver disease [MELD] score), rather than solely relying on waiting times. Primary care physicians are often involved in the long-term management of liver transplant patients, especially preventative care.

Correct Answer: B

Rationale: Sudden, severe pain may indicate a perforation, a medical emergency requiring immediate physician intervention to prevent complications like peritonitis.

Correct Answer: B

Rationale: Sudden, sharp abdominal pain is a key sign of perforation, indicating a breach in the stomach or duodenal wall requiring urgent attention.

Correct Answer: A

Rationale: Duodenal ulcer pain is typically relieved by eating due to buffering of acid, unlike gastric ulcers where pain often worsens with food.