Expect a sad little prawn, possibly moping about, whinging/whining, sleepy, maybe pukey or may not want to eat...
He might be a bit stoned, might not, he may appear absolutely fine - some dogs go very pathetic and cry a lot after the anaesthetic, it is usually the anaesthetic wearing off rather than pain but do make sure he has pain killers, some vets seem rather shy of giving painkillers! We know Pod + Pain = Twatdog.
He should recover pretty fast once the anaesthetic is out of his system though so expect a return to normal around 24/36 hours post op.
They send them home when they are sure they're awake enough and Ok... some wills tay a bit longer, noiseybois get booted out faster...
Expect vile VILE farts and shits after anaesthetic.
Experiment with pants/something that covers that part, I would avoid coning unless absolutely fucking vital because i find it really really upsets most dogs (fucks with their spatial awareness), also the damage a big dog can do to your shins and calves with a cone on is spectacular.
He may well leave it be, I don't mind them having a quick check and a brief lick, as long as its not a concerted effort to unstitch themselves or over wash, I think 'seeing what the fuck happened' is fair do's really!