Cholecysto-urachal fistula.

The urachus is an embryonic remnant that connects the primitive bladder to the allantois. Multiple urachal anomalies have been described, including the urachal sinus, urachal cyst, patent urachus, and urachal diverticulum. We describe an unusual case in which a patient with urinary tract infection and dysuria was ultimately found to have urinary gallstones from a urachal connection with the gallbladder.