Imaging of ischemic colitis.

Ischemic colitis accounts for more than half of all cases of gastrointestinal ischemia and constitutes between 1 per 2000 and 3 per 1000 acute hospital admission. It typically affects elderly patients, being a frequent cause of rectal bleeding, abdominal pain, and diarrhea. This article describes the epidemiology, physiology, and pathology of this underdiagnosed condition; reviews the clinical patterns of this disease, which constitute a key diagnostic point in patients who have a thickening of the colonic wall; and describes the ultrasound (US) and CT findings, pitfalls, and differential diagnoses of ischemic colitis. The value and limitations of US and CT at the different diagnostic stages is discussed.