Antibiotic-associated colitis

1. Big picture

Antibiotic-associated colitis is most importantly Clostridioides difficile infection (CDI): diarrhea and colonic inflammation occurring during or after antibiotic exposure. It is a classic hospital-acquired / healthcare-associated infection, but it can also occur in the community.

The exam pattern is:

Recent antibiotics or hospitalization + watery diarrhea + fever/abdominal pain/leukocytosis → think C. difficile until proven otherwise.

C. difficile causes diarrhea and colitis, can be life-threatening, and most cases occur during antibiotic treatment or shortly after finishing antibiotics. Antibiotics disturb the normal gut microbiome, allowing *C. diff