Questions about bladder

Hi, My Kobe is 5 years old and has never been sick,till now. Usually you can't get him to stop running or playing. I took him to the vet 2 day ago and they told me something showed up in his blood work to do with his liver( I don't remember exactly what) So I took him back in they did a urinalysis and he had a bladder infection. They kept him over night to start antibiotics and some pills for his liver. I didn't get a chance to speak with the vet when I picked him up. This was a new vet to us because we just moved. Anyway, He has been sleeping for about 24 hours now only getting up a couple of times. He does eat and drink, but when should I start seeing him feel better? And at what point to I take him back to the vet if he doesn't start getting better. We have a check up again in 2 weeks.
Thanks I am going out of my mind with worry and could use any advice.

Call your vet for more information about the results and explain what is going on.

Are you feeding your cat high quality food? If it was purchased at major pet stores or supermarkets, it's not high quality. Garbage in, garbage out.

I am feeding them Iams multi cat and they have been on that for over a year.