Safety and clinical efficacy of flexible sigmoidoscopy and colonoscopy for gastrointestinal bleeding after myocardial infarction

The risks versus benefits of flexible sigmoidoscopy and colonoscopy performed within three weeks of myocardial infarction were studied in nine consecutive patients who underwent sigmoidoscopy and in nine consecutive patients who underwent colonoscopy at two university hospitals. Indications for sigmoidoscopy were red blood per rectum in seven and occult blood in the stools in two. Sigmoidoscopy provided the diagnosis in three, including colon cancer in two and bleeding internal hemorrhoids in one, and provided helpful information in three. Sigmoidoscopy led to colon cancer surgery in two patients, and polypectomy of a 1-cm adenoma in one. Of two highly unstable patients before sigmoidoscopy, one developed second-degree heart block and frequent premature ventricular contractions 3 hr after sigmoidoscopy. No sigmoidoscopic complications occurred in the seven relatively clinically stable patients. Indications for colonoscopy included red blood per rectum in five, occult blood in the stools in three, and melena in one. Colonoscopy provided the diagnosis in five, including one each with colon cancer, internal hemorrhoids, large adenoma, ischemic colitis, and angiodysplasia. Colonoscopy resulted in colon cancer surgery in one patient and endoscopic polypectomies in three patients. Of two moderately unstable patients before colonoscopy, one developed asymptomatic bradycardia during colonoscopy. No colonoscopic complications occurred in the seven clinically stable patients. This study suggests that recent myocardial infarction is not an absolute contraindication to sigmoidoscopy or colonoscopy, that sigmoidoscopy is beneficial in medically stable patients with significant gastrointestinal bleeding, and that colonoscopy may be beneficial in selected, highly stable patients with significant gastrointestinal bleeding. Endoscopy should be performed with monitoring by electrocardiography and pulse oximetry after stabilization of vital signs, which may require transfusion of blood products and supplemental oxygen administration. Sigmoidoscopy in highly unstable patients and colonoscopy in moderately unstable patients may have a high complication rate.