Update on Colon Ischemia: Recent Insights and Advances.

Colon ischemia (CI) is the most common manifestation of ischemic injury to the gastrointestinal (GI) tract. This usually self-limited disease is being diagnosed more frequently, and the list of known causes is increasing. Local hypoperfusion and reperfusion injury are both thought to contribute to the disease process, which manifests with a wide spectrum of injury including reversible colopathy (subepithelial hemorrhage and edema), transient colitis, chronic colitis, stricture, gangrene, and fulminant universal colitis. The distribution is usually segmental with left-sided disease (e.g., inferior mesenteric artery distribution) being more frequently observed than right-sided involvement (e.g., superior mesenteric artery distribution). Any portion of the colon can be affected, but the anatomic distribution of CI recently has been shown to be associated with outcome. Patients with isolated-right colon ischemia (IRCI) have a different presentation and worse outcomes than other distributions of disease. Although somewhat variable depending on disease location, CI presents with cramping abdominal pains over the segment of colon involved followed by a short course of bloody diarrhea. Diagnosis is usually made clinically and is supported with serologic, radiologic, and colonoscopic findings. Colonoscopy is the most accurate diagnostic study. Most patients respond to conservative supportive therapy although some with more severe disease require antimicrobials and/or surgical intervention.