I believe that Remi was intended for healing the colon of ulcers, and then once you have the clear colonscopies, you might have the chance to go off of it. If that ever does happen, I'm sure your doctor will find a maintenance med that will work for you. It's been said that once you are off Remi, you might build up antibodies to the drug, although I've seen people go off and go back on it just fine.
Also note that I couldn't tolerate mesalamine meds either and was rather nervous having to take them again...but it turns out to work very well for me. With that being said, our bodies are very different and constantly changing! What works for some, won't for others.