Silent perforation: an iatrogenic complication of colonoscopy.

A 55-year-old woman presented with a complaint of 3 months of bloody diarrhea with an approximately 8 stools per day. She initially underwent a flexible sigmoidoscopy at an outside hospital with biopsies showing acute and chronic colitis. She was started on asacol 2 tablets 3 times per day. Her symptoms persisted and she was placed on prednisone with only transient improvement in her symptoms. She continued to have diarrhea and malaise with 30-lb weight loss over 2 months. Outpatient colonoscopy was performed for evaluation of this change in bowel habit. Colonoscopy showed 2-cm terminal ileal polyp, focal ulcer of the cecum, and severe ulcerative colitis from mid-ascending colon to rectum, with touch friability, spontaneous bleeding, pseudopolyps, and ulceration. Multiple biopsies were taken of the friable and ulcerated regions. After colonoscopy, the patient remained stable with no complaints of pain. She was then taken for computed tomographic enterography showing severe colitis but also reflecting a large amount of air surrounding the right abdominal structures including the liver, gallbladder, right kidney, and right side of the colon. Air extended inferiorly into the right thigh and superiorly into the chest where it reached the mediastinum and pericardium. There was also a small amount of air in the peritoneal cavity under the diaphragm and adjacent to the liver. These findings were thought most likely secondary to asymptomatic colonic perforation secondary to colonoscopy. The patient remained stable, afebrile, and pain-free small bowel pathology from colonoscopy revealed carcinoid tumor of the terminal ileum. The patient remained stable despite intraperitoneal, retroperitoneal, and subcutaneous free air on follow-up x-ray. Patient underwent elective ileocecectomy 2 weeks later with postoperative films showing no evidence of free air. Iatrogenic perforation of the colon is a rare but feared complication of coloscopy with an incidence in some studies of 0.03% to 0.09%. This case demonstrates asymptomatic colonic perforation to a dramatic effect.