I had being trying to get my doctors to prescribe me something for the pain for almost four years without any success. The reason for not allowing me opiates / opioids is that it could lead to constipation that could bring on or worsen a flare. The only thing they could say is paracetamol (acetaminophen) which is totally useless for this sort of pain.
Luckily though, as relationships have been built between myself and the doctors & nurses, I have recently been allowed to use cocodamol (which I believe is the same as tylenol with codeine. This is the 30mg/500mg version.
All I can say is I wish they had given it to me sooner. Not only has it helped ease the pain, my BMs are more regular and less, erm, messy. I have feeling the best I have in years - and the fact that I'm not on steroids is a bonus.
Admittedly, I only have mild to moderate symptoms, so I am not sure if a worse condition would have as good results. If my experience is anything to go by though, I wish this sort of management was offered as an option in the past instead of going to the more nasty drugs!