USMLE Step 1 Question 349

Question:

A 45 year old male comes to the emergency department complaining of severe abdominal pain and non-bloody diarrhea. On examination he has fever. He was recently in the hospital for 7 days for treatment of pancreatitis, and was was given antibiotics during his stay. He has not traveled recently. What is the most likely cause of this man’s diarrhea?

Correct Answer: D.  Pseudomembranous colitis

This man most likely has C. difficile colitis following his hospital stay and antibiotic treatment. Pseudomembranous colitis is characterized by diarrhea, abdominal pain (which can be severe), and fever.

(B) This man has not traveled recently, which makes this diagnosis less likely.

(C) The clinical history is not consistent with IBS.

(A,E) This man does not have systemic symptoms that would suggest inflammatory bowel disease. The proximity to his hospital stay and antibiotic treatment makes C. difficile colitis more likely.