Both intraperitoneal and extraperitoneal colonic perforations have been reported after colonoscopy; however, cases with combined types of perforation are rare. We present the case of a 55-year-old man with a history of Crohn disease who complained of acute abdominal pain after a diagnostic colonoscopy. Abdominal computed tomography scan showed extensive pneumoperitoneum, pneumoretroperitoneum, pneumomediastinum, and leftsided pneumothorax. Exploratory laparotomy was performed, and the patient underwent subtotal colectomy and end ileostomy with placement of a left-sided chest drain for the left-sided pneumothorax. The patient was discharged home postoperatively in good condition. As the utility of colonoscopy continues to broaden, its complications will also be more common. Whereas intraperitoneal perforation is a known and not uncommon complication, extraperitoneal perforation is an uncommon complication. Combined intraperitoneal and extraperitoneal perforation is extremely rare, with only a few cases reported in the literature. Early diagnosis and operative management resulted in a satisfactory outcome in this particular case.