This is an endoscopic procedure performed under a general anesthetic or conscious sedation to investigate mostly the bile ducts. Certain procedures can be performed such as removing gallstones from the bile duct. Stents can also be placed for cancer of the bile duct or forms of narrowing. Spyglass can be performed at the time of an ERCP.

This procedure can be performed at ERCP or when a laparoscopic cholecystectomy is performed for a laparoscopic bile duct exploration. It has many uses but may be used to remove bile duct gallstones or to biopsy lesions to exclude cancer and facilitate diagnosis.