Magnesium sulfate / potassium sulfate / sodium sulfate
"I have had 20 colonoscopies or so and have had mostly Golytley 4 liters in the past. Hands down this is the easiest prep I have ever had to do. Doing a split prep was awesome and in the past I had nausea, vomiting, and severe pain. With Suprep I didn't even cramp. Clear liquids the day before the procedure helps. 
I would pay full price for this, you have no idea how much better it is than what has been available in the past."