Unusual biliary fistula

Agenesis of gall bladder is a clinical rarity, as most of the diagnoses are made at autopsy. Preoperative diagnosis of this anomaly is fraught with follies. External biliary fistulae are usually result of complications of trauma or biliary surgery. Internal fistulae on the other hand may result from erosion of wall by a stone, cancerous growth or peptic ulcer. Sites of opening of internal fistulae are stomach, duodenum, jejunum, ileum or colon. These should be suspected if gas shadows are seen in biliary tree.