Two days ago I had my routine colonoscopy (I have UC so I have to them every 3 years). I felt OK afterwards just light occasional pain in one spot in lower left abdomen. Took off that day and the next. Today went for a bit faster run (not tempo but higher aerobic run) over the hills. First 30 minutes absolutely no problem but then suddenly felt quite powerful pain in lower left abdomen. In about minute or two I was unable to continue running anymore. Obviously felt scared but continued to slowly jog back and after couple of minutes the pain disappeared. Went for an easy jog in the evening and felt fine. I feel some strange sensation there like strained muscle or something. Does anybody know what the hell could this be? I had some biopsies taken, could they have injured my bowel, maybe some microinjury? I called my GI but she didn't have a clue just told that these might be gases which doesn't seem likely since I have never experienced anything similar.