Accidentally Ate Gluten in Coping with Celiac Disease Posted August 17, 2014 · Report to Admin I have been gluten free for almost 2 years. I have had the occaisional accident. I think everyone reacts differently. I find I don't feel much right away. Maybe a few hours later I will feel really tired and foggy, maybe have an upset stomache, and then it goes away within an hour. But prolonged exposure (I ate gluten 3 days in a row to see what would happen) causes me to be full out symptomatic. I ate it the first day, nothing. Had it the second, felt kinda gross. By the third day, I was heading into migraine city within an hour of consumption. For me, I wouldn't get fully sick after an accidental bite or two. I may not feel so hot but I will be functional. Everyone is different though, My sis in law is down for the count, in bed after a bite or two.