HalfLytely and Bisacodyl
"I had to use this for a colonoscopy. I was given a choice of 4 flavor packets, I chose the cherry. It didn't taste bad at all. I've spoken to people who said this started working within 30 minutes after beginning to take it. For me it took almost 2 hours. Since it took so long I was able to finish the entire container before I began having movements. Because of this I felt very bloated but that diminished once it started working. It's very thorough but there's no discomfort with it. It also didn't keep me up all night. It started working around 7 pm and stopped by bedtime so I was able to get a good nights sleep with no getting up during the night. However, from 7 to 10 I was going every 15-20 minutes. It was much better than I expected."