Haven't done, know I need too, can't stand the thought of drinking the prep! Last time I had to drinkl stuff for an ultrasound, I puked all over the waiting room floor. First half went down fine, ( this was the chalky stuff) next 1/4 I started gagging, last 1/4 oooopps! But, back to prep for colon., our pharmicist told my hubby, put it in the freezer, get it to the point of having ice crystals, and drink it as fast and steady as you can. He said the colder it is, the easier it is to get down.