Thank you for your concern and your advice! I don't know if she'll recover from this ever, but your suggestions do give us a few things to try instead of feeling hopeless.
For the past year or so my cat, Willow, has been getting sick every once in awhile (there doesn't seem to be a pattern). She has the same recurring symptoms of throwing up yellow bile, not eating, and not drinking. Multiple expensive tests at the vet, and we still have no answers as to what...