Unexpected discovery of Clonorchis sinensis by common bile duct exploration.

Coexisting choledocholithiasis and Clonorchis sinensis infection are relatively rare. We report a 39-year-old patient with choledocholithiasis who inadvertently found Clonorchis sinensis during common bile duct exploration. Our experience suggests that if preoperative imaging reveals nonspecific changes associated with choledocholithiasis, the possibility of biliary parasite infection should be suspected.