@tynakinnon: I had one at 27. It’s not fun, but it’s really not as bad as you think it will be. Every clinic has a slightly different prep protocol, but mine was:
Monday night right after dinner: drink one bottle of magnesium citrate. This really wasn’t too bad — it tastes like really sweet soda. Drink it over ice. This didn’t really do a whole lot in terms of time spent in the bathroom. I was able to go to work the next day like normal.
After I drank that, I couldn’t eat anything until after the colonoscopy on Wednesday. I was restricted to clear liquids like water, tea, coffee (without creamer), broth, apple juice (no orange or pineapple, nothing with orange, red, or purple dye), gatorade, etc.
Tuesday night at 4pm: mix up “colon lavage solution,” (1 gallon), drink half of the gallon between 4 and 7 pm. They recommend drinking 8oz every 10 minutes. This part sucked. I read on the internet to drink it through a straw — do.not.do.that. Just chug it, seriously. My doctor said I could add a little lemon juice to the solution and that made all the difference. You’ll be in the bathroom within an hour, so you don’t want to be away from home.
Wednesday morning at 7am: drink the other half of the “colon lavage solution,” same procedure as the night before. I couldn’t have anything to drink (or eat obviously) after 10am, and my procedure was at 2:30pm.
The procedure wasn’t that bad. They’ll put an IV in and give you some good drugs. Unfortunately, I don’t respond to one of the drugs well, so I didn’t get the full effect but most people say the drugs are the best part. If they work, you shouldn’t remember much if anything about the procedure, you’ll get kind of loopy, and you’ll need someone to drive you home and get you some food.