Hi Carol. Rain's had chronic vomiting most of the 7 and a half years I've had her. She would throw up partially digested food at least every other week, but typically more like weekly. About a year and a half ago my vet and I started to work her up for possible food allergies vs. intolerance with diet trials, switching her from the Wellness core she had been on, to science diet I/D, then to the current diet of Royal Canin Hydrolyzed Protein (we tried Z/D before that, but that's what led to the 3 day hunger strike). On the I/D she seemed to digest the food more before throwing it up, but the hydrolyzed protein seems to have resolved the vomiting related to her food. The response to the diet change along with concurrent scaly itchy ears (which are prone to ear infections) is what led to the diagnosis of a food allergy vs IBD or food intolerance. At this point, she does still have occasional vomiting, but it seems to be related to other causes (she's very prone to hairballs for instance; and she's a major foreign body eater, loves to chew on plastic). I do think the food allergy diagnosis is more likely than IBD given the skin issues she also has, but I guess that doesn't rule out IBD. I do wonder if she has some degree of pancreatitis though as well.
At this, point, I have yet to ever get Rain to eat wet food voluntarily (even when I met her as a severely ill 8 month old kitten, she wouldn't eat wet food), and she's very picky about trying new things (I once got about 30 different kinds of cat treats to try to find one that she would like to use when I was getting her used to her inhaler; she only ate 1 of the kinds, and even that she stopped eating after they changed the packaging and presumably the formulation). I'm hesitant to try any food that has chicken in it, as that was in every diet she's been on previously (turkey, pork, and some fish were as well), so I'm trying to limit my choices to novel protein or limited ingredient diets. Unfortunately Epigen 90, Evo, Waggers, and Young again all contain proteins that have been in foods that she's had problems with in the past, which is why I'm trying the Epigen Venison instead for a dry kibble. I've gotten some Nature's Variety, Ziwipeak, and Addiction canned food and have tried several of them - so far the only thing she's done has been trying to bury the dish. Right now, I think I have several options to try, I'm just still struggling with getting her to try them.
I'll add carrageenan and guar gum (I think that's the gum you're referring to) to my list of no nos!