Stomach pain. My stomach pain? any tab?

Been suffering from UC for last couple of years. Had got my colonoscopy done 3-4 times, sigmoidscopy done as well. Was admitted 4 times for the UC in last 2 yrs. I've been taking Mesacol OD two tabs per day. But last few days my stomach is paining a lot. Took a consultation on practo for the same as well but I was again adviced mesacol od. I've been using mesacol and vsl3/ probiday along with methyford etc. I was on omnacotril for few days as well. My recent colonoscopy was incomplete as there was a small bend in my intestine. So the biopsy said it was SRUS. All the other biopsies of the completed colonoscopy showed active colities. What is the difference between the two and why isn't my pain subsiding ? Can someone suggest something for my stomach pain? Any tab? Many a times I had to get IV administered for severe pain. I used to use Ultracet for severe pain as well. Now Im not using anything other than Mesacol so please suggest some med for stomach pain as I'm not able to even sleep.