My dogs diet

Question
Hi there! My dog has been throwing up yellow foam for years. Recently, when I took her to the vet, they put her on the Hill's I/D diet, which i am not sure i like. The vet said that she had problems with her anal glands, but she has never had a problem before. They told me she needs a high water content in her diet. It is too expensive, and it gives her really horrible gas, and sometimes she won't go potty (as of late). I think there isn't enough fiber in her diet. Help me please! what should I do, what should I feed her? I have never given her alot of treats, and when I did, they would be human grade treats.. now i don't give her any. I can't keep spending 90 dollars a month for food that I'm not sure is doing the trick. I really need help.

Answer
Good afternoon, Stephie.

Well, we'll see if we can find a food that will be helpful to your dog.

First, we'll need to know when and how often she is vomiting yellow bile like she is.  Second, what food were you feeding prior to her change over to the I/D?

Gail