I had mine out a month ago. Smoked about 6 or 7 hours before. Didn't get sick after the surgery. I'd think eating before surgery would be a bigger risk for sickness, as the stuff will make ya bit queasy but if you don't have anything in your tummy, you should be fine. Don't smoke afterwards, this WILL slow the healing, trust me (ya ya they warned me, but smokers are stubborn). For afterwards, try to get something other than Tylenol 3's. I've been taking those for so long for my migraines that no tylenol ever does anything anymore and didn't do crap for my pain. I suffered thru with no pain reliever, which just WASN'T FUN. lol. It also took me alot longer to get "back to normal" than the "3 or 4 days" they generally say. (smoking and no pain relief were the causes, really). Good luck to ya!