Reconstructive surgery of the aortoiliac junction often requires interruption of the inferior mesenteric artery. Ischaemic colitis following this type of surgery occurs in 15-20% of cases, most often in the splenic flexure and the sigmoid colon. It is caused by general haemodynamic factors and/or atherosclerotic changes in the intestinal arteries. Clinical symptoms are often subtle or atypical and the diagnosis is difficult. However intestinal ischaemia causes considerable morbidity and mortality. Around 1000 aortoiliac reconstructive procedures were performed, with a 2.8% incidence of post-operative colonic ischaemia. The two most important risk factors were hypovolemia and ligation of the inferior mesenteric artery.