My 12 year old ate something with "Malt" today...he's MISERABLE

I have 4 sons. I have celiac as well as my 2nd son, my 12 year old. Although he hates being different and can be self conscious about it around friends/at school, he is generally very cautious. He reads labels, he asks in restaurants. He knows who will pay if he eats the wrong food. Even his brothers and cousins look out for him and joke that he's like the Hulk, if he eats gluten he will turn green!

Well, half way through the day he was holding his belly, doubled over, in pain. He said he must be sick with something else, because he knew he didn't eat gluten. He's been miserable and suffering for hours. We went over everything he ate today, then I grabbed the box of cereal my oldest had chosen (who doesn't always read labels) and there it was...Barley Malt. It's been a very painful lesson for him. Now that he's gotten so used to feeling well, just having that one small ingredient has kicked his @ss.

By and large the rest of the household is gluten free at home, but I'm going to have to mark anything that comes in the house that has any gluten with a sharpie...NO!!!