Cat - blocked urethra

Question
I just had my male cat at the vet for three days -- he had a blocked urethra.  I brought him home on Thursday -- on an antibiotic and pain medicine. He started to urinate on his own on Friday midday -- and has stopped (for the most part) the somewhat bloody discharge.  He still won't eat -- hasn't since a week ago Monday - and now his muscles seem to be twitching.

Answer
You need to get some food in your cat asap. He is going to have worse problems than a blocked urethra if he doesn't. Get him some canned food, any kind of canned food that smells really fishy.
I am really surprised the vet would send him home not eating. That is something we never would do. That cat would stay until it was eating.
Ask your vet for a half of a valium and give your cat one quarter of it with a bowl of food right in front of him. Most of the time that will make them start to eat within about 10 minutes. Once they start tasting food again they usually will eat.
He is feeling toxic still which is one reason he isn't eating.
This is a really serious problem as you can see with his muscles twitching. That is usually from lack of potassium- one of the things they lose a lot of when they are toxic.
Hopefully he got some kind of fluids once he was unblocked.
Call your vet tomorrow about the valium (diazapam is what you want) and tell him the about his muscle twitches and ask why he was sent him while inappatent still.
I hope he does ok. Please keep me informed.