How to take it: Two 5-ounce doses, the first followed by five 8-ounce servings of clear liquid; the second followed by three 8-ounce servings of clear liquid. Prep: Polyethylene glycol, sodium sulfate, sodium chloride, potassium chloride, sodium ascorbate, and ascorbic acid (Moviprep). How to take it: Two 1-liter doses, each followed …