I'm 35 and had my first colonoscopy earlier this year. I was diagnosed with Celiac disease last year and was having significant GI discomfort even after going gluten-free, and the GI doc could tell I was concerned, so he suggested a colonoscopy just to rule out polyps or cancer. I dreaded the procedure, but in all honesty, it was a piece of cake (other than the cost). The prep isn't much fun, but you know that going in. My advice would be:

-Stock up on the softest toilet paper available. Someone in my house had decided to make the switch to single ply the week before my colonoscopy. One day I will offer forgiveness....but not yet.

-Get a cushy toilet seat. Otherwise, your legs will hurt from all the time you spend sitting there.

-Be near a toilet when you take the first dose of prep cocktail. It works fast. I think it kicked in within 20 minutes for me (I took Suprep).

Once the prep is over, you have nothing to worry about. The anasthesia works amazingly fast (I was given propofol). I think they told me to count backwards from 10 and I maybe made it to 7. At that point, you will feel like you were immediately teleported to the recovery area, and it will all be over. All in all, it's really not so bad.