The invention provides, in part, polyhydroxylated bile acids for treating biliary disorders, for example, biliary disorders arising out of cholestasis or portal hypertesion. The invention also provides, in part, polyhydroxylated bile acids for stimulating bile flow. New compounds 2a,3a,7a,12a-tetrahydroxy-5ß-cholanoic acid and 3a,4a,7a,12a-tetrahydroxy-5ß-cholanoic acid are disclosed, uses thereof and synthesis thereof.