Vancomycin Treatment in Recurrent PSC in Liver Transplant Patients

Inclusion Criteria: 1. History of prior orthotopic liver transplant or liver and kidney transplant. 2. Recurrent PSC confirmed by clinical labs (AST/ALT greater than 19 or ALKP greater than normal), imaging (MRCP or ERCP), and/or liver biopsy consistent with recurrent PSC. 3. No clinical evidence of liver transplant rejection and stability of post-transplant immune suppression dosing for three months prior to enrollment in the study 4. No changes to therapy for inflammatory bowel disease for at least three months prior to enrollment (for patients with history of IBD) 5. Patients on ursodiol must have been on a stable dose for two weeks prior to enrollment and dose must be stable for the remainder of the clinical trial. 6. All patients with inflammatory bowel disease must have had a colonoscopy within a year prior to enrollment 7. No antibiotics for 2 months before starting vancomycin 8. No probiotics for 1 month prior to starting vancomycin or during study period Exclusion Criteria 1. Allergy to vancomycin 2. Pre-existing advanced malignancies 3. Pregnancy or Lactation 4. Inability to provide consent 5. Findings suggestive of liver disease of other etiology such as chronic alcoholic liver disease, chronic hepatitis B or C infection, autoimmune hepatitis, primary biliary cirrhosis, hemochromatosis, Wilson's disease, or congenital biliary disease. 6. Current biliary obstruction 7. Active infection 8. Involvement in any other investigational study