About four days ago, I switched all three of my cats to a new food (mixing it with their old food for now). Since then, one of them, Esmeralda, has been vomiting, and now today has diarrhea as well... I know these things can be caused by a change in diet, but, what really concerns me is that she is not throwing up food, but a clear bile, and the diarrhea is very bloody and has what appears to be a white mucousy substance in it... is there any way that a change in diet could be responsible, considering this, or does the presence of blood and whatever the white mucous is mean that the problem must be something else, and it's just a coincidence that it's onset occurred around the same time I changed the food? Regardless, I am going to take her to the vet tomorrow, but I just want to get an idea of whether this might be the result of changing her diet, or whether I should definitely expect it to be something more serious. Thanks very much.