Do you happen to know how ingesting gluten for a celiac disease child plays a role in the ability to focus and concentrate at school?
There have been some studies which suggest that untreated celiac disease may predispose children to behavioral disorders such as ADHD. However, larger studies are needed to know for sure whether or not there is a connection. Interestingly, most of the studies which propose a connection between celiac disease and behavioral disorders suggest that a gluten-free diet significantly improves behavioral symptoms. If your child is experiencing difficulty with concentration, my advice would be strict adherence to a gluten-free diet. If behavior is still a problem despite a strict diet and a normal celiac panel blood test, I suggest discussing this with your pediatrician.
Center for Celiac Disease at The Children's Hospital of Philadelphia