Colonscopy...I highly recommend that you don't have this done if you're young. If you have parasites, start eating garlic everyday. I had a sigmoidoscopy done and my proctitis flared up like never before. Don't do it, don't do anything invasive.
Seriously, you and only you can fix your BM problems. I've been taking IF#2 and my bowels have improved greatly, along with my proctitis. You should take up swimming, or going for long walks. Try yogic breathing.