Can 'someone' have a phat bong and still be ok for surgery tomorrow?

my 'friend' is really craving a smoke of marijuanna due to just finishing uni exams and not doing it for ages and needing to clean his room (weed will make it way more fun!). but can he have a smoke today and not have the drugs interfere with his surgery? the surgery is an inguinial hernia repair and he will be under anaesthesia and knocked out. could the mix of drugs, if weed is still present in his system, interfere with the surgery????