I've had 7 colonoscopies by now. First one in 1997. I was a nervous wreck, the nurse kept telling me that the worst was over and to relax. Relax I asked? Was she nuts? LOL
She was right. If you can tolerate a needle prick, the absolute worst part of the actual procedure is getting the IV. Once it's in and taped down, you are set. They sedate you long before any scope goes inside. You wake up in recovery, feeling groggy, thirsty and you end up sleeping off and on for the rest of the day.
My tip would be to take along a water bottle and saltines for the ride home. When they offer you a drink in the recovery room, just sip it, don't down it. I downed an entire glass of Coke and it all came back up 15 minutes later. By then I was dressed and ready to go home. Yep, I was a mess. The nurse said it's best to nibble on a salty snack (pretzles are a good choice also) and sip water or 7up. By the time you get home, you may want to eat a light snack or lunch. I usually keep a bowl of Club Crackers and a Pepsi near my bed. I nap for a few hours and by then I want a light lunch (half of a turkey sandwich, soup, etc.). By dinner time I am feeling almost back to normal.
For some patients they are able to go out to eat afterwards (make sure you have your driver, you cannot drive or consume alcohol for 24 hours) but I've never felt that well. Even though I'm starving and very thirsty, I find it best to resume solids and liquids slowly.
Also, you'll pass gas for a while. Another incentive to go home and not sit in a restaurant. But that's my opinion. They pump air into the GI tract and it will work it's way out after the procedure is over. All normal.
Good luck! When you hear people complain about their colonoscopy, 99.9% of the time they are complaining about the prep. The actual procedure is nothing to worry about.