I think this is different for each person but I’ll relate my experiences. I suffered several bad symptoms for 45 yrs. First was diarrhea several times a day and then mental distress at night and waking up feeling like a crazy man. Now when I get something I shouldn’t eat if bad enough with gluten I will get immmediate flash diarrhea. If more subtle gluten exposure or maybe even something else I will have a bad night. I can usually pinpoint what food caused my problem but not always. Usually it is me “cheating” with something I really shouldn’t but is supposed to be GF and eaten before without problems. I will give a few examples; Morrell link sausage is labelled GF and I have eaten some that caused no problem but the last time it made me sick. Was it hidden gluten or the preservatives?? I don’t know but no more Morrell links. Lay’s potato chips are supposed to be GF but the last time I had some I got the night time distress. Was it gluten or something else? Don’t know but no more chips or any kind. One time it can be clean of offending ingredients and the next time kick my rear! Once I have found this to happen I no longer eat that food and it’s getting to where I’m more Paleo diet because of eliminating the last vestiges of my “cheating”.