Holy Smokes!!!

What kind of Doc are you going to?
I would recommend that you go to a Colon and Rectal Specialist (someone who has completed a Fellowship in this specialty). If this is not possible, I would at least go to another G.I. Doc. In Metro Detroit, we have a monthly area magazine that also once a year puts out a TOP DOC Issue-you might have something like this???
Request to whomever you go to "LISTEN TO ME!" Tell them you NEED a Colonoscopy or a CT Scan. This is not NORMAL and I can't believe that this Doc wouldn't try to rule out anything more serious. Speak up and take charge of your own health-you bark @ the moon until someone listens.
I'm sooooo sorry you have to deal with such yokels
Jen