Cholangioscopy in Primary Sclerosing Cholangitis (PSC)

Inclusion Criteria: 1. Confirmed diagnosis of PSC 2. Clinical indication for ERCP per local standard of practice, such as suspicion of potential malignancy based on worsening cholestatic values or clinical presentation (such as itching, cholangitis) or new biliary stricture on trans-abdominal imaging (MRI/MRCP, US or CT) or suspicious cytology 3. Diameter of bile ducts deemed sufficient to accommodate the cholangioscopy system based on imaging performed prior to scheduled ERCP 4. Written informed consent from patient to participate in the study, including compliance with study procedures. Exclusion Criteria: 1. Contraindication for an ERCP or POCS 2. History of liver transplantation 3. Mass/metastasis extrinsic to the bile duct identifiable on diagnostic imaging 4. History of iatrogenic bile duct trauma, including biliary surgery within 6 months of enrollment 5. INR \> 1.5 or platelets count \< 50,000 6. Age \< 18 years 7. Pregnant women or women trying to become pregnant