me myself i don't wait for any of my snakes to poop before feeding again i go by how active they become if they are going all over there cages in search of food they are hungry(now if they got an odd shape or a hard belly i don't feed) but other then that i feed every Friday and 9 out of 10 times they poop on Saturday or Sunday. my blood is usually the one that don't fallow along the norm like the others. going on a month 1/2 since my blood pooped but she's grown a few inches in that time and no hard mass in her belly. but bloods can go 6 months with out pooping I've heard and read. never had one go that long on me so can't say for sure but others have.
but yeah i would get him her in to see vet asp even if vet tells you drop it off and he'll work on it after hours for you i myself would want it to stay with the vet a few days after if any surgery is done. most say thanks to the admin for the new info on prolapses and good to know they are getting better at dealing with them last time i heard of a green doing this they say once it happens expect it to happen again. and the stitches would help keep it from happening again