I think the traditional guidance has been to go for your first colonoscopy around age 50. My doc mentioned that they're recommending that move down to 45, because they're seeing more and more young people with issues. You should bring this up with you doc if you have any similar symptoms or if there's any family history of colon cancer.
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Bullshit. I've got Crohn's, and have had more colonoscopies than I can count since age 13. About 75% of the time, I'm throwing up due to the prep. The prep is the WORST part.
It has gotten better over the years. If you go for one, do NOT let them give you the jug full of powder. I've had much better luck with prep-o-pik.
The other PITA is they generally won't let you go for the procedure by yourself, since you're under anesthetic and don't trust you to get home OK. That means you have to find a friend who is willing to wait 2+ hours for you.
I didn't particularly enjoy it, but it wasn't a problem.
I think people will have different tolerances to different protocols.
I will say though, after having the colonoscopy, my general bowel symptoms(never ending gas, mostly) improved dramatically. I'm thinking about doing a chemical cleanse every year just to keep things working fine.