Caffeine post op?

My doc told me I could have caffeine or tea ( no diet soda), but for every ounce of caffeine I have, I would need to drink an extra ounce of water.  I'm having enough trouble drinking water I wasn't going to add to my list so I just switched to decaf.  If I had caffeine withdrawals they were while I was in the hospital, and I had so many other things to worry about there.  I don't really miss the caffeine.