[Obstructive colitis induced by laxatives during colonoscopy preparation after ischemic enteritis and improved by endoscopic fecal removal: a case report].

An 84-year-old male patient who was diagnosed with melena was admitted to the hospital with ischemic colitis. During the preparatory procedure for colonoscopy, he reported severe abdominal pain and exhibited decreased blood pressure. Obstructive colitis was suspected, and a colonoscopy was performed. A large amount of hard stool was found in the sigmoid colon, with ulcers and erosions exposing the submucosal layer observed on the proximal side. The endoscope was able to pass through the ileocecal region, and the patient's symptoms subsequently improved. The decline in intestinal function following ischemic enteritis may have contributed to the passage obstruction. Although fecal obstructive enterocolitis is extremely rare, caution is warranted during colonoscopy preparation.