I'm 19 now and in my opinion I think it isn't just "triggered" I think the villi gets to the point where it can't take it (gluten) anymore... And bam symptoms galore... Im not sure if I am right so please correct me if I am wrong!!
I only think this because I went back to gluten for a while and at the start I was okay but I got sicker and sicker as time went on... So I'm not sure... Maybe that's something to do with how sensitive you are... Haha okay getting off track... I'd love to know more aswell about it all