<human>: Summarize the given text in a few sentences.

So, last week my cat started throwing up everything that she was eating.  We came home one day, and there was about five different piles of throw up covering our room.  We fed her again that night, and once again she threw up.  Some thing the next morning.  That morning, we found that she had actually thrown up blood, and that's when we decided to take her to the vet.

Well, the vet took her temperature, felt around, and said that there was no indication that she was sick.  He gave her a shot of anti-acid and send some stomach medicine home with us and said to monitor her for issues.  Well, that night, she threw up again.  Then she went to use the litter box and nothing came out except a big glob of blood.  I kinda loose it because my cat experience has taught me that this means there is a blockage, which means surgery, which means a lot of money that I don't really have.  However, it's our cat, so I'll spend what I can to help her.

Next morning, we bring her back for xrays.  X-rays showed nothing.  The vet called us in and said that the next step was blood work, although her was a little puzzled.  She still had no fever, she was extremely active. He said that if we had not told him about the symptoms, he would have given her a clean bill of health. Well, we got the blood work, and the next day the results showed nothing.

Well, it's been a week since then, and she is still throwing up.  However, if we monitor her intake of food, she can keep it down.  This morning however, I just realized that Indigo Moon: Solid Gold, the food we used, changed there recipe, and we started feeding her the new bag around the same time as getting the food.  Now we are going to try a new food and see if that helps...
<bot>: Cat got violently ill, spent $400 on tests that showed nothing.  Realized that the food we were feeding her switched ingredients and that's most likely the cause.