I'm having one later this month. Lucky I found someone to take me and drive home. The procedure is on a Friday, but on Monday of that week, I can't have anything with nuts or seeds in it until after the procedure. Then starting that Wednesday - no raw fruits or vegetables. The day before only clear liquids and they can't be red, purple or orange - well, there goes all the good tasting gelatins. No dairy and no sweeteners, just coffee, tea (no creamers or milk or sweeteners, and no red, purple or orange beverages). I guess that leaves water.