You got it.
We’ve been doing that, then using the syringe to feed it to her. Up until last night, that’s the only way she’s eaten for about a week.
Sending good thoughts for a full kitty recovery! Glad your vet was able to identify the problem.
Is she still grooming herself?
Take a clean washcloth, get it soaked, and rub it on her fur over her back and flanks. She’ll get really hydrated afterwards. Repeat as often as you can catch her. May hate you, but it tends to be an easier process on cats than trying to syringe-water them.
Likewise for food - get some soft stuff, and rub it on her nose. When she licks it off, try to get her attention onto more of it right below her - sometimes that initial stimulation is a perfect trick. I’ve also had friends take a paw and stick it in the food - they’ll lick that off for a good long time. That doesn’t work for mine tho - they all have their claws and don’t like their feet being messed with.
Good luck!
My dog has diabetes and is on a prescription diet - which she hates!
She stopped eating in the mornings, because she hates it - but a diabetic needs consistency so the vet sold me prescription wet food to mix in. (I am of the opinion that a dog will when it is hungry, but I also understand the reasons for consistency, so I dutifully mix it in.)
Glad they found the cause and sending out wishes for a quick recovery!
Oh poor kitty, and poor you 
I hope she finds a more comfortable place to deal with it, and eats and drinks more soon. It’s gotta suck not wanting to eat 'cause it hurts; my first thought was ‘gall bladder issues’ but 1. Not even sure cats have gall bladders and 2. I figured the vet would have found that, if that was it. I wonder if cats like peanut butter, hrm…