There is a difference between food intolerance and food allergy.
And there are different tests out there (some quite expensive) with varying degrees of reliability.
Also, some people can test either falsely positive or falsely negative, so beware.
Years ago, before I had UC, I had an expensive LEAP test done (blood test) and it was very interesting; it revealed a scale of intolerance from highest to lowest: coconut, spinach, tomatoes, fig, acetaminophen, red dye #, grapes, and a whole bunch of other stuff I really don't recall.
Interesting thing is that when I cut out those foods, I did feel better.
I did find out on my own that my body did NOT like: egg whites or bananas.
And then of course: Gluten, Wheat, and Dairy as well.
So my list has become quite large. But that's ok. I would rather know than not know.