Gastrointestinal: Sigmoidocecal fistula diagnosed with colonoscopy

Abstract

A 42?year?old woman underwent a colonoscopy for evaluation of abdominal bloating of three months' duration. Colonoscopic view revealed a large collapsed fistulous opening of the sigmoid colon. The ileocecal valve was identified when the colonoscope was passed through the fistulous opening connecting with the sigmoid colon. When the colonoscope reached the cecum through the conventional intra-luminal technique, white numbers corresponding to the colonoscope insertion length markings could be seen through the fistulous opening (Fig. 1). The appendiceal orifice opening was normal. To confirm the fistulous opening, indigocarmine dye was sprayed into the cecum. The blue dye was found in the sigmoid colon confirming the fistulous connection (Fig. 2).Double contrast barium enema and abdominal computed tomography (CT) scan were also performed. The barium enema also demonstrated the fistulous opening with contrast connecting the mid sigmoid colon and the cecum. Abdominal CT scan also demonstrated an air?filled fistulous tract that extended from the mid sigmoid colon to the cecal pole. However, there were no pericolic inflammation, mesenteric infiltration or bowel wall thickening around the lesion.Colocolonic fistulas are usually a complication of an inflammatory or neoplastic process. However, she had no prior history of any of the predisposing factors related to colocolonic fistulas. A thorough search of English literatures revealed only two cases of sigmoidocecal fistula due to sigmoid diverticulitis or granulomatous colitis. A radiologic study with contrast media is usually used to diagnose intra-abdominal fistulas. In addition, the primary role of colonoscopy may directly visualize the lesion that caused the fistula, and if needed, confirm through histopathologic review. In this case, chromoendoscopy was utilized to prove the presence of the sigmoidocecal fistula during the colonoscopy.