348 Cholecysto-Colonic Fistula Leading to Gallstone Ileus and Colonic Perforations: A Rare Surgical Case Report

Abstract We present the case of a woman in her 70s who was admitted with a 2-week history of mild, colicky lower abdominal pain with intermittent sharp exacerbations, associated with early vomiting, nausea, and reduced appetite. She reported no bowel movement for 7 days. Her medical background was unremarkable apart from a childhood tonsillectomy, and she was not on long-term medications. Clinical examination revealed diffuse abdominal tenderness, particularly in the right upper quadrant (RUQ), left and right iliac fossae, and suprapubic area. PR examination revealed soft stool without bleeding. Vitals were stable except for mild tachycardia. She underwent emergency exploratory laparotomy due to clinical suspicion of intra-abdominal sepsis. Intraoperatively, two small bowel perforations were found in the caecum and proximal sigmoid colon, with free intraperitoneal air. A large obstructing gallstone was found in the sigmoid colon, with a cholecysto-colonic fistula. Subtotal colectomy with end ileostomy and subtotal cholecystectomy was performed. Due to the gallbladder remnant’s close proximity to the common bile duct, Callot’s triangle was not dissected; instead, a Foley catheter was placed into the gallbladder remnant and secured with an omental patch. The postoperative course was notable for initial hypotension requiring vasopressor support and intensive care admission. Persistent bile drainage from the subhepatic drain and leukocytosis prompted HPB MDT review, which advised against ERCP. A repeat CT abdomen/pelvis showed no new abnormalities. The patient recovered well with ongoing stoma education and was successfully transitioned to ward care. This case highlights a rare presentation of colonic gallstone ileus due to cholecysto-colonic fistula.