Magnesium sulfate / potassium sulfate / sodium sulfate
"This is the worst prep ever! Last time I had a colonoscopy I did the moral ax prep and it worked well with no gagging taste, no cramps and no nausea. This time my GI has changed to suprep- worse taste ever, had a hard time holding 1st dose down, vomited 2nd dose, worst cramping ever and burned my skin in the backend when everything came out. WHY do doctors use this when there is a much more tolerable medication on the market? Pure torture!"