Ischemic colitis is caused by ischemic damage to the wall of the large bowel, particularly the colonic mucosa. The cause is sometimes unclear but most patients are elderly (90%) with some evidence of vascular disease. Only a minority of patients have well-defined precipitating factors such as hypovolemia or episodes of hypotension. Typical symptoms include abdominal cramps, abdominal pain and rectal bleeding. Abdominal pain is often located on the left side of the abdomen as the most commonly affected areas are the descending colon, sigmoid colon and splenic flexure. The usual outcome is improvement in symptoms within 48 h and healing of mucosal lesions in the colon in 1–2 weeks. Serious complications such as colonic gangrene, perforation and peritonitis are rare.

Approximately 5% of patients with ischemic colitis have an obstructing lesion, usually in the distal colon. Half of these patients have colon cancer while the remainder have strictures caused by disorders such as diverticulitis, radiation and previous surgery. The endoscopic images from one such patient are shown in Figures 1 and 2. The patient was a woman aged 76 years, with intermittent rectal bleeding for 7 days. The cancer was located at the rectosigmoid junction (Fig. 1). After passage of the colonoscope through the stricture, the mucosa just proximal to the neoplasm was normal. However, there was an abnormal region, 15 cm in length, in the descending colon and upper sigmoid colon. The mucosa was red and edematous with small submucosal hemorrhages and linear erosions (Fig. 2). Biopsies were consistent with ischemic colitis. The association between colonic obstruction and ischemic colitis may be related to reduced colonic perfusion associated with colonic distension or changes in colonic motility.

  1. Contributions to the Images of Interest Section are welcomed and should be submitted to Professor IC Roberts-Thomson, Department of Gastroenterology, The Queen Elizabeth Hospital, Woodville South, South Australia 5011, Australia.