My 6 yr old son has bad b.o. after he eats certain foods(which?) also has bad cavities, only 1of4 kids. could be celiac or sensitive to dairy?

Cavities: His cavities are probablty due to the fact that he was put to bed with a bottle of milk or juice. The milk sugars or fruit sugars remained in his mouth while he slept thereby causing cavities. If you keep a food diary you may be able to find out which food is causing his body odor.

Child neglect: If your child has such bad cavities that you can smell the infections, he must see a Dentst ASAP before damage spreads to other organs. Go now! If smell is not from the infections, after a thorough examination your Dentist will be able to direct you to the appropriate medial practitioner for appropriate treatment.