<<Disclaimer: Verify this information before applying it to your situation.>>
One of the basic premises of food allergies is that a reaction is
not always immediate. In fact, it can take up to 72 hours for
a reaction to show up although it is very difficult to pin a reaction
72 hours later on one food you ate three days ago. We've seen
reactions that can be directly attributed to food 10-14 hours later
(like tomato sauce eaten at dinner causing a bad tantrum at school
the next day).
I don't know if celiac reactions can be that delayed since gluten
reactions are not due to "allergies."
Jean Jasinski