DS (age 6) was circumcised in the Summer - it was a 'day surgery' and we were done in an afternoon and we were home by teatime (went in about 12.30, home by about 5.30).
Immediately after the op DS cried a bit but I think that was mostly shock and confusion if that makes sense, I don't think there was much pain. He ate a little bit of a sandwich, managed to have a wee (they like them to do that before they go home) without too much trouble and we went home. He did throw up in the car but I'd put that down to him having inherited my crappy reaction to anaesthetics!
Once home he polished off a good half of an adult pizza and went to bed. He slept the night through which surprised me. When he woke up the next morning he did howl a bit which I suspect was due to all the painkillers wearing off etc. We basically kept him dosed up with calpol/nurofen (we did the alternating thing) for a few days afterwards. He was pretty much fine through all that period - a bit tired and cuddly but we basically had a lazy few days on the sofa watching TV etc. It's important to let the 'air' get to it to help with healing - we were advised when at all practical long t-shirt and no pants is the way to go.
The hardest bit was having to put the antibiotic cream on (3 times a day I think - it was GoldenEye ointment so quite 'fiddly' as it's very thick - we got the knack of almost 'piping' it out through the nozzle and then very gently almost stroking (rather than rubbing) it in. Not sure how you'd handle that with a 9 year old as DS was only 6.5 and so had no qualms about letting us manhandle him.
By about day 5 or 6 he was getting bored of sitting watching TV so I took that as sign he was well on the road to recovery and we started doing more stuff. I'd hold off things like bike riding, trampolines etc for a week or so but I know some kids who were bouncing around after a couple of days...
You also get advised to shower not bath for the first week.
It might be different with a 9 year old but a few weeks later when we were checking DS was healing ok when he got out of the bath I commented that it had all healed nicely and he commented 'but it hasn't grown back yet mummy' - bless him, amongst all the explaining and preparation we'd done with him it hadn't occurred to us that he'd thought it would be like hair, fingernails, teeth etc and if you lose some you get more
.