From 1975 to 1985, a total of 1596 coronary artery bypasses or valve replacements resulted in 18 gastrointestinal tract complications in 16 patients at Good Samaritan Hospital in Cincinnati. Twelve patients were treated surgically (hemorrhagic duodenal ulcer, one patient; perforated duodenal ulcer, one patient; cholecystitis: acalculous, gangrenous, two patients, and calculus, one patient; perforated cecum, one patient; ischemic colitis, one patient; and perforated diverticulitis of the colon, five patients). Six patients were treated conservatively by either nasogastric intubation or nothing by mouth and intravenous therapy (ileus, three patients; acute sigmoid diverticulitis, one patient; and active peptic ulcer disease, two patients). Multisystem failure caused two deaths. The etiology of hollow viscus complications seems to be related to a low-flow state, impairing normal tissue perfusion that can initiate an ischemic change. This change can lead to acute inflammation, perforation, or both or late stricture. When evidence of an acute abdominal disorder is observed or when conservative treatment falls to alleviate symptoms, prompt surgical intervention should be performed.