Since I was a little kid, I was sick all the time. After years of tests with no diagnosis, I finally figured out gluten was the culprit at age 22.
My provider told me to cut gluten from my diet and that I likely had celiac. Before I completed the blood tests, I had been gluten free for some time, so they weren’t 100% conclusive. I also had the biopsy but years after going gluten-free. For me, it wasn’t worth it to reintroduce a food that was making me sick for 4 months just to get a conclusive diagnosis.
I just continued the positive changes that made me feel healthier. Unfortunately, cutting out gluten wasn’t enough. I was still having a lot of GI issues so I further limited my diet, restricting dairy and other processed foods.