Magnesium sulfate / potassium sulfate / sodium sulfate
"The taste was the worst part, followed by all the water. I mixed the first dose with white cherry powerade after reading the recommendations of some the reviews, and I wish I hadn't. That made it worse. I could hardly stomach it. My instructions said to drink it within 20 min, but I think it took three or four hours for me to finish 70% of it. I gave up on the rest and poured it back into the little bottle so I could use the water cup, and after my stomach calmed down attempted to drink the remainder. It was easier drinking it out of that little bottle since I couldn't smell it. The second morning dose mixed with plain water was much easier to swallow. Bowels were liquid fairly quick, though weren't clear until 2hr before procedure."