I had such a horrific reaction to the FLEET that I will never ever try this again at home. I started violent nausea in about a half hour, and it only got worse. The diarrhea wasn't near as bad as I expected; it was the nausea and weakness and fever and chills and pain that nearly did me in. By 9 pm or so I was on the verge of calling an ambulance to come get me. I had the heat up to about 80 and was on the couch under two wool blankets and still shivering. By the time I had to stop fluids I was bloated on water and tea, but by morning I was parched and desperate. It was 2 hours after my appointment time when I finally got in for surgery prep, and by then I thought I'd die.
The colonoscopy itself wasn't a big deal -- I'm notoriously difficult to sedate and I'd warned the doc and the anesthetist that I might try to wake up and kill them. They had me completely down.
If I have to do this again I will check in to the hospital the evening before, pay for the extra day with cash if necessary, and have them start me an IV before beginning the prep.