I knew one poor dude with Chrons. It came and went randomly, and he tried all these pain killers that never worked. The doctor told him Oxycontin won't help, but I think he may have lied because he was a young male, and a bit of a spaz who liked to party... the doc didn't trust him, perhaps???
I would think the doc didn't trust him; prescription narcs can be a very slippery slope. I do remember when I was in nursing school, and one of my first patients was a 30-something male with Crohn's, who was admitted to have a central line inserted (IV line in a large vein in the chest) to receive TPN (nutrition through an IV). I distinctly remember that he was on rather large doses of methadone and Percocet. It can be a very painful disease...