Spyglass cholangioscopy is the direct examination of the bile ducts using a small caliber scope which is passed through the ERCP scope. The Spyglass scope can be inserted into the bile duct or pancreatic duct to enable direct visualization during ERCP and help obtain biopsy specimens, lead to the diagnosis of abnormalities, and to do laser lithotripsy for large bile duct stones which cannot be retrieved without lithotripsy