Intraperitoneal and Extraperitoneal Colonic Perforation Following Diagnostic and Therapeutic Colonoscopy with Crohn's-related Stricture Dilation.

Colonic perforation is an uncommon but known and feared complication of colonoscopy, which carries a high mortality rate. We present an uncommon case of extensive intra- and extraperitoneal air following colonic perforation in a patient undergoing inpatient colonoscopy for evaluation of unintentional weight loss and constipation. During colonoscopy, a splenic flexure stricture was identified and dilated. Postprocedural hemodynamic instability prompted further imaging which revealed pneumoperitoneum, bilateral pneumothorax, pneumomediastinum, pneumopericardium, and severe subcutaneous emphysema. Emergent exploratory laparotomy found perforation of the proximal transverse colon which required resection and transverse colostomy placement. The patient also underwent bilateral chest tube placement and was treated with antibiotics for peritonitis. The patient was eventually diagnosed with Crohn's disease and discharged to an extended care facility with outpatient follow-up. Extraperitoneal colonic perforations are fairly rare, and to our knowledge, we present the most severe case that has been published in recent years.