We report the case of an 82-year-old lady who presented with large bowel obstruction. The computed tomography scan revealed an obstructing gallstone in the sigmoid colon. At colonoscopy the stone was seen in the sigmoid colon proximal to a diverticular stricture. After balloon dilatation of the stricture under general anaesthesia, the stone was removed. This approach should be the treatment of choice; only if this fails should surgical treatment be considered.