sorry to hear about your kitty. my cat, patsy, has a sensitive stomach that flares up every now and then. she'll be fine for quite a while, then she'll start to vomit frequently (daily). the vet puts her on prednisone and that seems to take care of it (she gets one pill a day, 5mg, for about four days, then a pill every second day to wean her off it). ask your vet. it's what works for her...
hope this helps!