I am surprised that they diagnosed you with ulcerative colitis, I have the same symptoms as you do and probably even more (bloating, gas, burning and painful colon 24/7, painful BM, sometimes diarrhea, often loose stools) and the Dr only said that I had a bad case of IBS.
Did you have a coloscopy done? If you have UC the intestinal lining is "ripped" up and raw, its a horrible condition.
Atleast from what I've read?