I agree with Dusty that it may not be realistic to expect total pain relief, but you're also right that remission isn't always achievable in every case either.
I take codeine and it's the best pain relief I've found, though I can't deny that tolerance and addiction are proving big problems. Nevertheless, I still feel a lot better taking it regularly than not - I've come off it several times, given it long enough that withdrawal is no longer an issue, yet I still feel noticeably worse off it than on, though not just in regards to pain. In this country at least (the UK) you won't get anything much stronger than codeine outside of hospital unless under exceptional circumstances. If codeine and oxycotin aren't enough, you're probably going to have to look for ways of dealing with pain besides conventional pain killers (though they may still have a place in treating your paint too).
Finding effective pain relief depends a lot on finding the right type of treatment for your type of pain. Some simple things can be surprisingly effective, for example, holding a hot water bottle on a cramping stomach can help because the warmth relaxes your muscles. Adjusting your diet may help with digestive pain. What type of pain do you have? Have you noticed whether anything makes it better or worse?