Cat is using the bathroom much less after neutering. Normal or not normal?

My cat is both peeing and pooping much less frequently after being neutered. It has been over a week since his surgery and he is playing as normal. He is eating and drinking less (which I heard is normal behavior since the decrease in hormones equals a need for less food). Is that the reason he is peeing and pooping less or is this abnormal. He used to poop once a day, now it's like once every day and a half. He used to pee 4-5 times a day, now he's peeing maybe two. He had a swollen kidney before surgery and was treated for a UTI before surgery. Is this normal behavior or does he likely still have a UTI?

UTIs typically cause more peeing not less. I'd say if he's eating and drinking less then he'd naturally use the toilet less. What goes in must come out as they say.

If his weight is normal and he's acting like himself he's probably fine. But ask your vet if you feel concerned.