Multibending vs Conventional Endoscope for Direct Peroral Cholangioscopy

Inclusion Criteria: * Pancreatobiliary diseases that are indicated for direct POC * The patient who aged from 20 to 80 years. Legally acceptable representative must be capable of giving written informed consent prior to participation in this study * The woman of child-bearing age must be negative from the pregnancy test in order to participate in this study * Dilated common bile duct (\> 8 mm) * Having previous sphincterotomy and/or papillary balloon dilation * The patients should not have any unacceptable conditions (e.g., physiological, familyish, social, geographical) for medical follow-up and adaptation of the study. Exclusion Criteria: * Contraindicated for ERCP * Patients with stricture on papillary orifice * Patients with periampullary malignancy * Bleeding tendency: International normalized ratio (INR) of prothrombin time \< 1.5 or platelet count \< 60,000/mm3 * Patients with other serious disease or medical condition * Patients with past medical history of significant neurologic or Psychiatric disorders such as dementia or seizure * Unstable heart disease despite of treatment, recent myocardial infarction within 6 month (Even though MI was diagnosed within 6 months, if it becomes stable presently, the patient can be possible to participate).