A Pilot Study of Xifaxan to Treat Patients With PSC

Inclusion criteria: * Diagnosis of PSC established by all of the following criteria: * Alkaline phosphatase \>1.5 times upper limit of normal for at least 6 months duration * Gamma-glutamyl transferase (GGT) \>1.5 times upper limit of normal in pediatric patients * Cholangiography demonstrating intrahepatic and/or extrahepatic biliary obstruction, beading, or narrowing consistent with PSC * Liver histology in the past (if available for review) with features consistent with or diagnostic of PSC * Both genders * Adults: Ages 18-75 years. * Pediatric: Weight \> 40 kg * Patient's informed consent for study participation Exclusion criteria: * Treatment with systematic antibiotics, Azulfidine, ursodeoxycholic acid, corticosteroids, colchicine, methotrexate, azathioprine, cyclosporine, chlorambucil, budesonide, pentoxifylline, tacrolimus, vitamin E or prednisone in the preceding three months * Active drug or alcohol use * Prior history of allergic reaction to the antibiotics which will be used in the study * Any condition that, in the opinion of the investigator, would interfere with the patient's ability to complete the study safely or successfully * Evidence of decompensated liver disease such as recurrent variceal bleeding, refractory ascites or spontaneous hepatic encephalopathy * Anticipated need for transplantation in one year (Mayo survival model \<80% one-year survival without transplant) * Findings highly suggestive of liver disease of other etiology such as chronic alcoholic liver disease, chronic hepatitis B or C infection, hemochromatosis, Wilson's disease, 1-antitrypsin deficiency, non-alcoholic steatohepatitis, primary biliary cirrhosis or secondary sclerosing cholangitis * Treatment with any study medications in the preceding three months * Pregnancy or current lactation; subjects becoming pregnant during the study despite all the precautions will be withdrawn and referred to their primary physicians