I am 6 day's post op. and I do feel a little down, but the protien drink ISOLATE is considered a clear fluid if made with water and it has 25grams of protien per 8 onz so i try to drink 4 glasses a day, you can buy this at a nutriution store. Also its very important to remember that when you become dehydrated its like a dried plant that has not been waterd for a long time -if you poor the water in to the plant fast, all the water will run out of the bottom, the same goes for us- you water yourself with little mouthfuls give your self time when drinking a glass if you gulp it will run out. I also drink a bottle of Pediatric-Electrolyte, I dont know if it does any good and it may be the same as Gatorade( just less surgar)...but i think it helps. best of luck, and make sure you have someone with you for the first 48 hours.