Magnesium sulfate / potassium sulfate / sodium sulfate
"Third colonoscopy but the first using Suprep.  Read a few reviews to inform myself and decided to use ideas of getting the 6 oz bottles really cold before mixing and drinking.  Took a half hour to kick in and since this process isn't easy for me to handle with carpet on floors, etc. I"ve been sitting for almost two hours now.  Things happen quickly and mentally I feel better in my bathroom rather than worrying about cleaning everything up.  The taste wasn't that bad; drank it through a straw as suggested by someone and drank the other two 16 oz already.  Second round is at 1:30 a.m. for a 6:30 appointment in the morning.  Hope I can get some sleep in between somehow."