Spontaneous choledochoduodenal fistula (CDDF) is a rare form of biliar
y enteric fistula which usually occurs as a complication of duodenal p
eptic ulcer disease. The more common form is cholecystoduodenal fistul
a (CCDF) which is generally associated with gallbladder disease. We re
port on a case of ulcerogenic CDDF diagnosed by upper gastrointestinal
barium study, ultrasonography, and gastroduodenal endoscopy.