Cholecystoduodenal fistulas represent a complication of cholelithiasis and is the most common type of enterobiliary fistulation.

CT demonstrates a fistulous tract between the gallbladder and duodenum and some ectopic gallstones. Pneumobilia is a common feature.

This condition can lead to Bouveret syndrome or gallstone ileus.

This patient was subsequently treated with laparoscopic cholecystectomy.