Limited sphincterotomy and endoscopic papillary balloon dilation (EPBD) is a low risk method in treatment of choleducolithiasis. But effective ballooning time is not clear. In this study, we compare five seconds and one minute ballooning time. This study is a unicentric, single blind, randomized clinical trial. This study is single-blind because participants will be deliberately kept ignorant of either the group to which they will be assigned, but the experimenter will be in possession of the ballooning time in each one. Sixteen to ninety years old patients eligible for treatment of choleducolithiasis, with no severe hepatic, biliary or systemic disease enroll in the study. Lack of consent to cooperate in trial, precut sphincterotomy or failure of cannulation of common hepatic duct will exclude the patient. After initial laboratory examinations, sixty patients randomly will be assigned to receive EPBD with either 5 seconds or one minute ballooning time after endoscopic retrograde cholangiopancreatography and small sphincterotomy. Maximum choledochal diameter, stone or stones count and largest stone diameter will be measured. Then stone or stones will be retrieved with balloon extractor. If stone or stones removed, the procedure is successful. Otherwise, it is unsuccessful. Serum amylase will be checked 2 hours after procedure. Patients will be fallowed 48 hours for abdominal pain, pancreatitis, perforation, hemorrhage and fever.