you avatar is sooo funny!
lol
Again the length of the prescription depends on your surgery and how much residual pain you feel afterwards. As for getting rid of the pain, it should work, though if you're having problems you can always talk to your doctor and get it changed for something else.
It's best to talk to your doctor about things like these. No two surgeries go exactly the same and they'll be able to fill you in on the particulars and exactly what course of action they'll take.