I had my first one two months ago after turning 50 last November. It's really not a big deal, a lot of people complain about the 'preps' to get ready, more about the taste more than anything else. You most likely already know you'll be on the pot quote a bit so there won't be any surprises there either. I did the magnesium citrate prep lemon-lime flavor, it tastes a bit tart and like you've got some Alka Seltzer in there too, a tad salty, but I didn't have any problems drinking it. Had it not been for the medical procedure, a shot or two of Gin would have made a tolerable gin and tonic,
The procedure itself will be over before you know it. If you do have any pain during the procedure, it will only be remembered as a dream. I remember (afterwards) about moaning in pain as the doc tried to work the hose around one of the curves in the colon. I remember when I did moan, he quickly worked his other hand around externally on my stomach to help the hose around the turn. So there may be pain but you'll only remember it like a dream, again not a big deal.
Mine was scheduled at 9 in the morning. So I had to get up around 4 am for the second round of prepping. They wanted me to start 4 hours before the procedure but my first round of prep the night before lasted 5-6 hours, hanging around close to the toilet, so I gave myself 5 hours to hopefully get it all done so I wasn't trying to hold it in on the way to the hospital, it wasn't a problem. An hour later I was done, home before noon, and then I slept all afternoon. No side effects afterwards, no pain, nothing. I am no longer afraid of this procedure.
BTW, they did find a benign polyp. I did have occansional bleeding. I feel good now for getting this out of the way. Good luck!