Pneumoretroperitoneum, Pneumomediastinum, Pneumothorax, and Subcutaneous Emphysema after Diagnostic Colonoscopy.

Colonoscopy is a commonly performed endoscopic procedure. Although it is generally considered to be safe, serious complications, such as colorectal perforation, can occur. Most colonic perforations are intraperitoneal and cause pneumoperitoneum with acute abdominal pain as the initial symptom. However, extraperitoneal perforations with pneumoretroperitoneum may happen, albeit rarely, with atypical initial symptoms. We report a rare case of rectosigmoid perforation occurring after diagnostic colonoscopy that developed into pneumoretroperitoneum, pneumomediastinum, pneumothorax, and subcutaneous emphysema, with a change in voice and neck swelling as the initial symptoms. The patient was successfully treated with endoscopic closure of the perforation and conservative management.