At the risk of being somewhat serious:
I had my first colonoscopy a few months ago. The doc said everything is fine. But I had mentioned that I had been prone to diarrhea for awhile, and he recommended a tablespoon of Metamucil (Psylium) in liquid a day. I take it most days, and things have been moving along a lot more regularly, so to speak. I've been getting in quite a bit more biking and hiking lately, too, which I'm sure doesn't hurt either.