Natural help for my cat instead of surgery?

Hello, everyone!

My husband and I adopted a cat about a month ago. He began vomiting quite often a few days after we brought him home. I took him to the vet immediately and he was diagnosed with Acute Gastritis. The vet prescribed Antibiotics , which I was wary of giving to my cat, but did anyway against my better judgment. He was having a terrible time taking that stuff, and continued to vomit every other day or so, so I took him off of it a few days before I was supposed to. The vet told me if the Antibiotics didn't work, he'd need to have surgery, as it may be a foreign object stuck in his body that he'd swallowed. But there's a huge list of other things it could possibly be. Can Antibiotics fail? I've heard very bad things about them.

The thing is, I'm against surgery unless it's absolutely necessary. If it were me in this situation, I'd want to try something natural before going through a surgery. There's no blood in his vomit, and he doesn't seem to be in any pain at all. He plays a lot, still likes to eat when it's time (though he still throws up his food sometimes), and uses the bathroom regularly. I was thinking maybe his problem is parasites, or even hairballs, and I've even considered going to another vet to ask for a second opinion. I dislike vets that mention surgery on the first day, unless it was obvious the animal needed it.

So I would like to try some natural treatments before considering surgery. Can anyone suggest parasite treatments, diets, even hairball remedies that are natural that I can try first? Maybe something that could help dissolve a foreign object in his body without harming him? I'm keeping a close eye on him. I'm considering taking him in for just xrays.. Anyway, any advice will be appreciated. Thanks! :)