An Formal Web page of America govt. This is how you are aware of we are official. dot gov icon Nonabsorbed ursodiol passes into the colon where it is generally 7-dehydroxylated to lithocholic acid. Some ursodiol is epimerized to chenodiol (CDCA) through a 7-oxo intermediate. Chenodiol also undergoes seven-dehydroxylation https://www.youtube.com/watch?v=A07qHOeWON8