Biliary ascariasis: an uncommon cause for recurrent biliary colic after biliary sphincterotomy and common bile duct stone removal.

Endoscopic retrograde cholangiography is the most commonly used technique for removal of common bile duct stones. Biliary sphincterotomy during the procedure facilitates stone retrieval from the common bile duct. However, sphincterotomy ablates the normal biliary sphincter mechanism. This facilitates duodeno-biliary reflex and can result in inward migration of luminal parasite into the biliary system. In areas where ascariasis is endemic there is an increased risk of biliary ascariasis in postbiliary sphincterotomy patients. We report an unusual case where a patient presented with recurrent biliary colic after cholecystectomy and common bile duct stone extraction and was diagnosed to have biliary ascariasis with the help of endoscopic ultrasound examination of the biliary system.