I take tramadol when needed. I find that it is pretty effective and doesn't effect me cognitively, so I can still go about
my day. Anything stronger just knocks me out. As a lot of people already said, if you are having pain, something is wrong. Either scar tissue, an abscess, or inflammation. The main goal should be to figure out what is wrong and tackle that. Pain meds should just be short term to hold you over unil you can take something that solves the problem.
I think a GI SHOULD give something if you are in pain. Misspriss - have you tried asking him directly? It sounds like the 6mp isn't working. I had the same type of pains when I was on 6mp. If your GI won't give pain meds, I would try your general practitioner. I don't think they should give you a hard time as long as it's just for temporary relief.