It depends on what is causing the pain. If it's inflammation, then the focus should be getting the inflammation under control with drugs other than pain medicine. If it's side affects from Crohns (joint pain, neuropathy, etc.), then you may need pain medicine long term.
Anti-spasmodics help with the cramping - there's a whole variety of them - Bentyl, Levocin, Donatol, etc.. Librium is the only thing that works for me, for some reason, even though it's not technically an anti-spasmodic. Most gastros or primaries will prescribe some type of anti-spasmodic, because they're not narcotics.
Also, anti-depressants can help with the pain.
But, if all else fails and the pain is going to be chronic, then it's narcotics. Vicodin works for me most of the time, but I have to get it from primary physician. My gastro doesn't prescribe any pain medicines. I've never had a gastro that will prescribe pain medicine. I've noticed, in this forum, that some people take Percocet, Darvocet, Vicodin, or even Oxycontin. Some get pain medicine from their gastros, some from their primary physicians, some from rheumatiod arthritis doctors, some from pain management clinics.
If you are having a flare up and are in severe pain, go to the ER. They can give you morphine and phenergrin, along with hydration, thru an IV.
Good luck to you and I hope you can find a way to get your pain under control. Pain management is always a controversial topic, unfortunately.