UCwhat? said...
Some people do not tolerate mesalamine well and have bad reactions that make it seem like the UC is just getting worse. I would definitely get in touch with your GI and make it clear that you are feeling worse. Good luck!
However people who are intolerant usually have much stronger reactions than bloating. You will not find a safer (on average) UC med than mesalamine. Be very sure you can't tolerate it before you move on to more toxic things. Maybe even try various brands and pill coatings ...