It's not very rare, it's just highly undiagnosed. My kid got diagnosed with celiac and it's hereditary so me and my SO had to get tested. I didn't have it, the

It's not very rare, it's just highly undiagnosed. My kid got diagnosed with celiac and it's hereditary so me and my SO had to get tested. I didn't have it, they do. Undiagnosed for decades. Switched to gluten-free diet and they feel SO much better now. But the thing is that humans are really adaptive, you don't know what "good" feels if you've been feeling bad all your life - that's your normal level.