Cat won't eat or drink after abdominal surgery?

Hi everyone. Hopefully I'm posting this in the right place. Our cat Simba was not eating or pooping on Monday and throwing up everything we gave him even water and bile, so we immediately took him to the vet. They had to sedate him to take an X-ray (he was not happy at the time). The vet said there "might" be something in his intestine but to wait. So we left him in overnight care at the vet where they had him on fluids all night. The next morning we took him home and he seemed better. He still wouldn't eat or drink or poop. We tried to give him his pain medicine (buprenorphine) and he immediately projectile vomited everywhere.

We again immediately took him to the vet. They did another X-ray (he was much calmer at this point so no need for sedation). They said they wanted to do surgery to see if there was anything in his intestine like they thought. We proceeded with surgery (sedation, intubation and fluids again). They found a button stuck in his small intestine. She pushed it up to his stomach and opened that up and removed it. He again stayed in overnight care and got fluids and pain killers.

We picked him up this morning and brought him home. Since then he still hasn't eaten (since Monday now) his stomach is completely empty and he still hasn't pooped or peed today. He pretty much got home, got out of his cat carrier sat down on some blankets and has been sleeping since (it's been almost 8 hours) He has been purring a lot when we pet him which is nice but he has barely moved. We tried to coax him to walk around but he just sits back down and sleeps again. My question is should we be worried or is this kind of behavior normal after surgery? Has anyone else experienced anything like this with their cat?

The vet said to wait until tomorrow morning to come back in if he hasn't eaten but we have been worried sick for days now. I was kind of hoping the worst was over with once we got the object out.

It isn't uncommon for a cat to refuse food after a surgery or when not feeling well. Considering his stomach problems I can't say I blame him. However, its not good for him to not be eating.

Usually when mine are refusing food I pick the stinkiest wet food we have, mix it with some water into a paste and push the bowl right under their nose. If they don't try to lap it up I will put a little dab on the tip of their nose; most of the time they will lick the dab off and take a few more laps of the food in the bowl. If that doesn't work...human meat baby food. The stage 1 tiny jars with no garlic or onion listed, chicken usually works really well. My cats will gobble that up even if they turn their noses up at everything else. 

Keep in mind, most cats when they are sick will fall back on instinct. One of those is to not eat when someone is watching. Even though they know and trust you they might refuse to eat when you are in the room. I know it is hard, but once you offer the food and put a dab on the nose you leave the room. Walk away, close the door, don't sneak a peek. My girl is a big on not having us watch her eat when she doesn't feel good and it is really hard to not want to check up on her every ten seconds. But in the end its for the best. 

@simbaandnala, how is your guy doing now?  Has he eaten on his own yet?  I'm guessing he may still have been a little out of it from the anesthesia the other day, and that may have been why he was sleeping so much and not feeling hungry. 

Hoping he's  better now.