i've had the same problem...had a colonscopy with terrible pain and diaherra and it showed up fine so he said i must have ibs on top of crohn's. I know the scope can only go up so far, so i was thinking maybe it was active higher up but who knows. He didn't seem to want to go the extra mile to find out if it was higher up. Frustrated cuz now i never know when it's suppositly ibs or if it's the crohn's, and he seems to not want to treat me based solely on symptoms. I told him, trust me, if it wasn't bad i wouldn't be wasting my time with these procedures and appointments.