The development of an acute abdomen after colonoscopy is a relatively rare event. Overall rates of colonic perforation are widely reported at being in the region of 0.12% (see ). Although colonic perforation is the most common cause of acute abdomen following colonoscopy, several other aetiologies have been reported. A Medline search (Data base: 1950 to 2007; Search term: Colonoscopy; Subheading: Adverse Effects; Limitations: Case Reports) discovered 49 reports of splenic injury, 14 cases of appendicitis, 10 cases of ischaemic colitis, 5 cases of small bowel perforation, 3 cases of cholecystitis, 3 cases of portal pyaemia, 2 cases of small bowel arterial thrombosis, 1 case of pancreatitis and 1 case of a ruptured iliac aneurysm following colonoscopy.
Mechanical bowel obstruction following colonoscopy has been reported by 21 other authors. Half of these have been related to volvulus of the caecum, sigmoid or entire small bowel mesentery. One case of caecocolic intussusception has been reported . Three cases describe the resolution of small bowel ileus or obstruction following conservative treatment. The authors note that each of these episodes occurred in patients who had previously had appendicectomy or colonic resection, suggesting that they are cases of adhesive small bowel obstruction precipitated by colonoscopy [4, 5]. This theory is supported by the observation of two cases requiring laparotomy and adhesiolysis of post appendicectomy adhesions [6, 7]. The remainder are related to incarceration within external or internal hernias. Inguinal hernias have accounted for three cases whilst one case of large bowel diaphragmatic herniation is reported.
Our case is one of only five in the literature relating to the internal incarceration of small bowel as demonstrated at laparotomy. These include a case of colonoscopy-induced sigmoid mesenteric rupture and subsequent small bowel incarceration through the defect , one case related to a postcaecocystopexy band adhesion , one case of ileal incarceration in a paracaecal hernia  and one case of incarceration in a mesenteric defect . It seems likely that inflation of the colon and small bowel combined with extensive manipulation is responsible for the development of internal incarceration. Such complications may be minimised by a good colonoscopic technique. This should utilise torque steering and the avoidance of extensive insufflation and pushing in order to maintain a straight scope and a short colon.