Had a colonoscopy back when I was 51... was told there were polyps (which were removed) and I should come back in 3 years. Just had the second colonoscopy... it came back clean. I was told to come back in 5 years.
Truth be told the colonoscopy is nothing... I was fully asleep both times. The prep for it just sucks though... if only someone could invent a solution that does the job without tasting like old spit. I can usually get the first 8 oz down, but after that, I have to really fight it.
Oh and as someone said, stay close to the WC... and bring reading material. Sheesh. Just when you think it is over... whoosh!