Clinically and endoscopically proved ischemia of the colon complicates elective aortic reconstruction in 1% to 2% and 6% to 7% of cases, respectively. Operative mortality exceeds 60% when transmural infarction occurs. A prospective study of colonic ischemia was undertaken in 100 male patients (mean age, 62.4 +/- 7.9 years) undergoing operation for aortic aneurysms (58) or aortoiliac occlusive disease (42). Conventional aortic surgery was undertaken in 88 patients, and in 12 patients adjunctive procedures to enhance colonic perfusion were performed 14 times, including IMA reimplantation (8), direct bypass to the internal iliac artery (4), and anastomosis of an aortofemoral bypass limb to adjacent common iliac artery (2). Colonoscopy was performed within 24 to 48 hours of aortic reconstruction. Three patients had endoscopic evidence of colonic ischemia. Transmural infarction did not develop in any patient, and bowel resections or diverting colostomies were not necessary. Three patients died, none manifesting colonic ischemia. The 12% utilization of adjunctive procedures to enhance blood flow in the colon was substantially greater than the 4% frequency of an earlier experience from our institution in which nearly half of the 5.7% operative mortality was attributed to colonic infarction. Attention to factors contributing to ischemia of the colon, and more frequent adjunctive revascularization of the colon, may lessen this complication of aortic reconstructive surgery.