Urachal-sigmoid fistula in an adult male.

Urachal cysts are unusual anomalies resulting from incomplete closure of the urachus. They comprise 38 per cent of urachal abnormalities. They present commonly in childhood, and there are only 20 reported cases of urachal cysts presenting in a person over the age of 40. Only one reported case appears of urachal-colonic fistula, and this was in the setting of colonic diverticulitis. This report presents the second reported case of urachal-colonic fistula and the first case of a fistula in a patient with a normal colon. The pathophysiology and management of urachal cyst are discussed.