Citric acid / magnesium oxide / sodium picosulfate
"This was my third colonoscopy and had never had problems before with other prep kits.    This one did me in.    I woke up the day of the procedure feeling queasy, and sure enough, about 40 minutes after drinking the prep, I was vomiting profusely.  I had to run the drug store to get magnesium citrate to complete the process, but got sick after that as well.   Luckily, I kept the latter down long enough to get the necessary affect.



My gastro was not happy that I'd had the problem.  He apologized profusely and said that was the last one he was prescribing.   Too many patients were reporting problems."