Hi again, thanks for your replies!
The vet has kept him in overnight, as Manson was doing little wees all over the place yet his bladder was still a little full....they have given him some medication so it will relax him and they can check if he relieves himself fully when not in pain. If he does then he will be able to come home straight away with some other meds and stuff but if not I think it may be crystal blocking the urine
They have just phoned to say he is settled for the night though, which is good
He never goes into a cattery, we have a very nice colleague with 9 cats at her home who comes and feeds our 2 little nippers twice a day and gives them a run around too x