GOT TO STOP THE DIET COKES PRE-OP!
You are not going to be able to have the carbonation after surgery, so it is good to go ahead and "break the habit" now. I don't know if I would try to go "cold turkey" because you can get some fierce "no-caffeine" headaches!! I would start sorta gradually and cut back a little bit each day. I recommend Crystal Light or Artificially sweetened Kool-Aid as a sub. It is not quite the same, but better than just plain water. Just be sure and keep yourself hydrated!!! Best wishes. Pam