Sudden food intolerances?

Hi. Several years ago I was told I had gastritis, GERD, lactose & gluten sensitivity. He told me to take Prilosec OTC & enzymes when I ate gluten/lactose. I remember it working for awhile but at some point it stopped working & I just dealt with the symptoms because I wanted to eat what I wanted to eat. Now I've been told I have Barrett's Esophagus, IBS, gastritis & I've been having pain under my right rib that radiates to my back I believe when I eat protein and/or fat. After being completely gluten-free for several months with no improvement & after researching fructose malabsorption, that seems to be the problem - getting tested on Friday. Stool results show fecal fat which requires more testing but no parasites, no bacteria...Long story short, has anyone with IBS found that they developed sudden food intolerances & figured out why?! Are the intolerances from the IBS or vice versa?