Cat, vomitting

Question
My cat has been vomitting throughout the day, 3 times as of 11pm today. I have changed her food from Iams to Purina Indoor formula, but it has been at least a month and she seems to like it. I was out of town for the weekend, could this be a way of her acting out? I did research that some cats do this when they overeat or eat too fast, which might be the case, even though I attempt to portion control her food. My parents may have overfed her while I was gone this weekend.  I didn't want to overreact, but she is so precious to me, and will take her to a vet tommorrow if necessary. Thanking you in advance, Misty

Answer
Try fasting her for 24 hours, then reintroduce the food in small portions.  If she continues to have vomiting, then I would take her to the vet.  Sometimes giving a small bit of chicken and rice is easier on the stomach than reintroducing the regular cat food after a fast.  You can also give some yogurt to help replace the good bacteria in her intestinal tract.