10yr old suffering episodes of stomach pain and vomiting with headache seems to be after certain foods. drs say migraine i'm not convinced i have gallstones and i'm concerned he may have also is this possible?

At your son's age, migraine headaches may be more focalized on GI symptoms, and as the child ages, the headache becomes more prominent. Of course, there could be other reasons for his symptoms, but I doubt gallstones are answer. Would not hurt to obtain images of abdomen, and get this more clearly objectified. Also, find a pediatric neurologist.