Pneumoretroperitoneum, pneumomediastinum, pneumopericardium, and subcutaneous emphysema complicating sigmoidoscopy: report of a case.

An 80-year-old woman presented to our outpatient center with abdominal pain and blood-stained stools. She underwent a colonoscopy, which showed a 4-cm type II tumor in the rectum. About 2 h after the colonoscopy, mild facial edema and subcutaneous emphysema developed around her neck. A chest X-ray showed pneumopericardium, pneumomediastinum, and subcutaneous emphysema, and an abdominal X-ray demonstrated retroperitoneal air. An exploratory laparotomy was performed on the second day after the colonoscopy, which showed air in the subserosal space of the sigmoid colon. The air seemed to have leaked from a 2-cm inflamed diverticulum in the sigmoid colon. The mesosigmoid was also expanded by air. We discuss the anatomical mechanism of the various clinical presentations of extraluminal air following colonoscopy.