Biliary colic with dilated common bile duct: simple "sheepish" problem?

A 40-year-old man, resident of a rural area of Rajasthan state of India presented with recurrent biliary colic and fever since last 2 years. Examination was normal and investigations revealed a dilated common bile duct with elevated alkaline phosphatase. Magnetic resonance cholangiopancreatography revealed a dilated biliary system without any evident cause. Patient was subjected to endoscopic retrograde cholangioancreatography and it demonstrated biliary dilatation with a linear filling defect in lower common bile duct, further sphinicterotomy was done and a live Fasciola hepatica was extracted using a biliary basket.