Side effects - most constipating opiate?

[jorg]

SWIM is blessed with a not-so-wonderful form of IBD called Crohn's Disease. SWIM has been relying on Imodium almost daily for about 75% of days during the past two years and is sick of the drowsiness and dizziness he gets from it. SWIM's doctors sometimes give him Oxycodone or Hydrocodone when he also experiences constant pain but his doctors are usually not very sympathetic. SWIM has noticed Oxycodone has the same effect as Imodium on his digestive tract while an equivalent dose of Hydrocodone has almost no effect on this part of his body. SWIM can easily function in his daily activities with the side effects of the non-Imodium opiates, but can't take the awful hang-over feeling he gets from Imodium anymore. If SWIM was to come across some sort of opiate (legally, of course), what would SWIM's best bet be to slow down his digestive tract as much as possible?