You need to have an agreement in place with your doctor beforehand with regards to the script for painkillers. Don't let him, push some weak-ass shit on you....scoff when he offers up Tylenol #3. Hold out for Demerol, low dose oxycontin, or something along those lines. I have a friend that needed to get circumcized at 18....he spent two weeks walking around in a bathrobe, never left the house...played a lot of video games. After that, it was a week or so wearing loose silk boxers and those baggy weightlifting pants that were popular in the late 80s and early 90s.
The key is the painkillers though. Get the good ones, and your suffering will be minimal.