yeah, Savaici is right. Those preps work lightning fast on me too, and nausea/vomiting is a big problem for me. You do need fluids, so try taking small sips as you can and make sure what you're drinking is not cold. Warm liquids will help relax your stomach more. I suffer with chronic nausea and have prescription medication for nausea/vomiting, and if yours gets bad, your doctor can prescribe you something. Sometimes walking around helps, sometimes just being still and breathing deeply into your lower abdomen helps. There is also an acupressure point on the inside of your wrist that you can massage that is surprisingly helpful. Two finger widths in from the wrist crease. Also, ginger or peppermint tea (if you're allowed those), can settle the nausea. Hopefully, the nausea will just pass as the cleanout gets fully under way.
