In agony after taking solpadol since gallbladder removal. Difference between solpadol and co-codamol?

I'll try and keep this as short as i can.

In april 2010 i started with severe pain in what i could only describe as 'my ribs'. Being only 19 at the time it took a while for me to be referred for an ultrasound and sure enough i had 3 gallstones. So after a year and half of hell I had my gallbladder removed in August 2011. While waiting for my operation i was prescribed dihydrocodeine to try and help with the pain (it didnt really) but the tablets themselves had limited negative effects other than making me a little drowsy. Also while i was still having gallbladder attacks I had taken Co-codamol in an attempt to help the pain and I had taken solpadol several time previously for other problems. However, about 6 months into having these attacks up until today i havent been able to take solpadol without ending up in total agony again, feeling very similar to a gallbladder attack. Since having my gallbladder out, after a couple of months, i tried dihydrocodeine - no pain, totally fine. On another occasion since the removal I have had to take a solpadol (thinking the pain it put me in before was something to do with my dodgy gallbladder) but sure enoough it left me in the same pain again. They both contain codeine so i can't see how it is that being the problem. Also, before my gallbladder removal i didn't have a problem wit co-codamol and could take them without this nasty side effect, but all i am reading is that solpadol and co-codamol are the same thing, which is confusing me since one leaves me in severe pain and the other doesn't. So basically now i am terrified of taking co-codamol since having my gallbladder out, but i never had a problem with it before, i'm obviously never going to take solpadol again in my life but sometimes paracetamol and ibuprofen arent enough. Can anyone relate to this or understand why i'm reacting to solpadol and didn't appear to react to co-codamol?