Had colonoscopies in 2002, 2003, 2004, 2006, and 2009. Next one will be in 2012.
(1) The first 4 I used (IIRC) the Fleet #3 kit. 4 small pills and 1 small bottle of liquid. The last time I couldn't - I was told that the FDA concluded the pills were a cancer risk. Not sure if I believe that. I had no choice on things, as each time it was the specialist who prescribed it.
(2) Light breakfast the morning before. Two slices of unbuttered toast. Black coffee only. Clear liquids only. Chicken broth okay also. Start drinking 4 ounces of fluids every hour beginning at noon. At 4pm you start taking your "medicine". By 5pm you're pretty much camping out in the bathroom until 9pm. By 10pm? You're so empty you pretty much fall alseep immediately.
(3) My specialist does them on Mondays and Wednesdays at a small outpatient clinic down the road. He does followup work from his office the other days. The first 4 times I was the first or second one he did that day. The last one was in the afternoon. I STRONGLY RECOMMEND TRYING TO SCHEDULE IT EARLY IN THE MORNING! Yes, the worst part is cleaning yourself out the day before, but if you have to hang around the entire morning after that (and you can't even drink water after 6am), you are a glutton for punishment.
(4) Once you're in the waiting are they have you change into a gown and they put an IV in. I usually waited about 10-15 more minutes before they wheeled me in. Not sure what kind of anesthetic they use, but they pretty much had me counting down from 100 and I was zonked out before I hit 90. Afterwards they move me to a recliner where I'm told I fart up a storm - it's a side effect. I'll take their word for it because I'm still not too aware.
(5) I do know that each time the specialist told me the results - but only once did I actually remember. I am required to have someone drive me home. No cab, no walking home. If I can't provide proof that someone will, they cancel.
(6) I greatly recommend having it done. They found non-cancerous polyps the first time and a small mass too new to say what it was the second time. One polyp this last time. As of now I'm considered "average" - meaning I'm 52, male, and I should have this procedure done every three years.
(7) Finally, there really isn't any good time of the year to do it. No matter what it's going to be 24-30 hours of your life gone in hopes of hanging around on this planet for years longer. I still work, so I usually leave for home at noon the day before the procedure and take a 2 hour nap afterwords. The first time I was told not to drive for 24 hours afterwords but I was actually bowling that evening.