Magnesium sulfate / potassium sulfate / sodium sulfate
"The first dose was rough, I was pretty nauseated by it but did not vomit. I spent about three hours in the bathroom and was able to get some sleep before my last dose at 4 am. With the approval of my doctor, I took a dose of zofran one hour before my second dose and this one went down much easier. No nausea and the taste didn't bother me as much. Colonoscopy is in four hours. Let's hope this prep did the trick!"