Abdominal pain with fever

A 57-year-old man with a history of inflammatory bowel disease (Crohn disease) and diverticulosis. He presents now with left lower quadrant pain and fever.

Findings

An air-fluid level is present within a well-circumscribed fluid collection that has an enhancing wall. This collection is adjacent to and contiguous with a thickened descending colon, that also demonstrates a diverticulum.