I believe there are two factors contributing to the perceived rise:
1. The US has lagged behind Europe significantly in their knowledge and diagnosis of celiacs disease/intolerance, so more people are finally being diagnosed.
2. The wheat in the US today is significantly different from the majority of European wheat [1]
This is purely anecdotal, but I (22) know a lot of people in my generation who easily get stomach aches from milk and gluten. I've had some problems myself. Really kinda sucks.
1. The US has lagged behind Europe significantly in their knowledge and diagnosis of celiacs disease/intolerance, so more people are finally being diagnosed. 2. The wheat in the US today is significantly different from the majority of European wheat [1]
https://recipes.howstuffworks.com/is-american-wheat-differen...