Saw a private heptologist last night. He has narrowed all my symptoms down to 2 possibilities:
Sphincter of Oddi Dysfunction (SOD)
or
Autoimmune Hepatitis
I have to come off codeine completely, remove onions and wheat from my diet (and dairy but I'm vegan anyway) for 6 weeks and then reintroduce slowly. Add some laxatives, have the liver biopsy and let's see what happens. He will then (apparently) be able to have a better idea what is going on.