A Rare Case of Cholecystoduodenal Fistula Complicated With Gallstone Ileus and Upper Gastrointestinal Bleeding.

Gallstone ileus is a rare presentation of cholelithiasis, which usually impacts the narrowest part of the bowel, the ileocecal valve. This occurs as a result of a bilioenteric fistula where a gallstone passed through and entered the gastrointestinal tract. It is most commonly encountered in elder patients and predominantly in females. Abdominal computed tomography is the investigation of choice for diagnosis in the majority of cases. Here, we present a 68-year-old female patient with a choledochoduodenal fistula complicated by upper gastrointestinal bleeding and gallstone ileus.