Digestive enzymes

I've been lurking about for some time gathering information to help treat my wife. I won't get into to much detail, but she has been sick for 10 months, went through all the conventional medical tests and ended up on anti-depressants. She is now back down to just xanax. We have been on the candida diet for almost a week along with all the other stuff.

The one thing I don't have her taking is digestive enzymes. What would indicate the need to take digestive enzymes? We are not yet sure if she has food intolerances yet, but it is a very good possibility.