3 year old Bengal unwell since Friday evening

Our normally friendly Bengal girl started being all hunched up and growling on Friday evening and today Wednesday is no better. She eats when I give it to her in her hiding spot. I guess she must come out to drink but that's it. She's been to the vets and all tests show nothing at all. She's had steroids and antibiotics but nothing helps. She's had X-rays. They even observed her overnight. No clue. Maybe something she ate they say but it been so many days.

Any idea what to look for now ?

Thank you.

When did you take her to the vet?

When did she get the steroids and antibiotic? One shot or dosing over several days?

When you say "all tests" do you know which they did specifically?

Is she using the litter box? Is it normal usage?

Was there anything that happened recently (visitors, moving, storms, new pets, new neighbors, etc) that could have startled her?

Did they x-ray just her abdomen and did they do top, side or both?  

Is she indoor only or does she go outside? If indoor only, have you noticed anything tipped or disturbed areas (maybe she got trapped or bruised which wouldn't be visible through fur or on x-rays but would hurt and make her want to just hide and heal, Link did that with his bruising but he has a white belly so we could see it)?

When she moves is she favoring a limb or hesitant to put down a paw? More like a scared cat moving or moving like something is hurting?

At this point a few more details will help fill in some blanks and give people more to go off of to offer suggestions or thoughts. I tried to cover all the bases with my questions so people have some direction in responding. Most of us have no medical training but sometimes you get lucky and someone recognizes it as something similar to a personal experience. 

From what is posted now I am not sure what else you could check or try. The details are a smidgen vague and don't add up. Gut is it is something more environmental then medical but  that can be hard to pin down and it is better to rule out medical first. 

Immediate suggestion would be if it has been more than 48 hours since the vet visit to contact another vet and get a second opinion. Not saying your vet is bad but sometimes fresh eyes and a different perspective can come up with a new approach. If you do that, make sure to bring all her medical records and results from the recent exam. Also take a video of her moving, video of her is she is reacting to specific movement or actions around her, and photos of how she is sitting. While it seems odd, sometimes behaviors our feline friends show at home they hide at the vet and those can sometimes be the key to understanding or a clue the vet might otherwise have missed.

She went to the vet Saturday, got a shot then and then back Monday. She stayed there until Tuesday afternoon. She had a second shot then. I know they did blood tests and ruled out things that way but I'm not sure what exactly. Im also not sure what X-rays but I think they took a lot. She doesn't seem to have any leg or other spot hurting. She seems to be going normally in her box. She is an indoor cat, might go out once in a while but mostly not. she is to go back to the vet tomorrow, with a stool sample.

Hmmmm

See what happens at the follow up. If she isn't improving after that I'd get a second opinion. Keep an eye out for dehydration and make sure she is eating.

Hopefully this turns out to be one of those cases where she randomly is better one day.

Growling is a sign of pain and combined with the hunched position, most likely pain-related.  From what, your vet still needs to determine.  Did the xrays show anything unusual?  Was a urinalysis done?  Is her oral health ok?

Anything unusual happen in the home recently, did she fall from something, spar with another cat, etc?

Yes, I'm sure she is in pain. I don't know if they checked her pee. I wonder if it could be something pee related they way she is hunched up. I will ask tomorrow. Nothing unusual has happened. She lives a happy life with her sons and almost never goes outside.