Ischemic colitis.

Ischemic colitis is the most common form of gastrointestinal ischemia. Patients present with either occlusive or nonocclusive vascular disease, although the latter is more common. Many causes of nonocclusive disease have been identified, but the exact pathophysiology remains unclear. Most commonly, patients develop abdominal discomfort and bloody diarrhea. Diagnosis is confirmed with colonoscopy. Treatment is contingent on the severity of disease: mucosal/nongangrenous ischemia requires only supportive measures and medical management, whereas transmural/gangrenous ischemia may require prompt surgical intervention. Ischemic colitis can also become a chronic process with persistent segmental colitis or colonic stricturing. The patient's outcome depends on the severity of disease, prompt recognition, and appropriate treatment.