A case of cholecystocolic fistula incidently found with a positive fecal occult blood test and finally diagnosed with endoscopic retrograde cholangiopancreatography

Abstract

We report a case of cholecystocolic fistula diagnosed by endoscopic retrograde cholangiopancreatography. A 77-year-old woman was referred to our hospital because a fecal occult blood test was positive and a colonoscopy showed a fresh blood clot of hepatic flexure of colon. Our colonoscopy revealed a submucosal tumor-like lesion close to the hepatic flexure of colon, and an endoscopic clip was placed around the lesion for further tests. Contrast-enhanced CT indicated that the gallbladder stuck to the colon around the clip and air was seen in the gallbladder. We suspected cholecystocolic fistula. We performed barium enema, drip-infusion cholecystocholangiography, and endoscopic ultrasound, which ended up with few clues. Finally, we performed endoscopic retrograde cholangiopancreatography, inserted a catheter into the gallbladder, and injected contrast material, which proved a fistula between the gallbladder and the colon.