bile duct spasms caused by codeine forte overload

I am Hep C+.  On 17 Nov 08 my GP prescribed Codeine Forte and Steroids for serious influenza virus which attacks the lungs.  7 days later I attended Emergency Centre.  My white cell blood count had doubled in 2 days, I was put on a drip and told by dr never to take any of the prescribed drugs or Ibruprofen again in my life.  I was given Tramal.  I have attended Emergency Centre a further four times.  The final attendance was on 20 December when I was put on drip of Buscopan.  Dr wanted to admit me for intravenous buscopan and morphine.  I opted to take buscopan and tramal + 4 x paracetamol a day orally and it does give some relief.  The option to be admitted remains if the pain is intolerable.

I would like to know how the drug overload caused my bile duct to spasm.  New GP's projected recovery time is end Feb 09.