Not eating after sedation and enema

How long should I wait for my cat to eat he had a sedated enema yesterday he has had a drink and a wee but no food      

Hello - I'm not sure under what circumstances your cat had an enema, what they were sedated with, whether or why your vet chose that, how systemically well they were or even how stressed or relaxed or in or out of pain they feel at the moment.  A combination of these things may determine how long it might takes a cat to eat - but they shouldn't go for too long if it can be avoided.   Your vet, who knows the case well, will be a good person to speak about this with - it is your vet and their emergency cover's responsibility to oversee an animal's wealfare after surgery.  Please do get in touch with them to talk things over.