Heavy mineral water. A very slight salty-metallic taste. You have to drink so much of it in a short period of time, so taste doesn't matter as much as tenacity. I suggest no meals, food anytime before four hours of taking it. It all comes out anyway. Expect a long night. Good luck. BTW; the name has nothing to do with the results. However, it is the choice of most doctors. Go-Lytely and Co-Lyte both come with a variety of flavor packets which can be provided by the pharmacist. It may be better to mix it and store in the refrigerator until cold for several hours before you drink it; this will help mask the slightly soapy taste of the product. Also ask you physician for a prescription for one Reglan 10mg tab to be taken an hour before drinking the GoLytely. This will help empty your stomach contents faster and reduce the bloated feeling.