As you know food allergy only affects 1% of the population and is highly over sought as a reason for gi complaints. Abdominal migraines may be the cause. Are the stools normal in color and consistency, does he have any changes in weight. Any other medical issues, family stress. Constipation is notorious for causing abd pain/cramping in this age group, but vomiting is usually something else. Acid reflux usually isn't associated w/ vomiting unless an impressive hiatal hernia exists. Make a diary of when he vomits, his stool habits and see a doc.
It could be cyclic vomitting syndrome(CVS). It is an adominal migraine. My son started having attacks of this at about age 3 to 4 years old. Unfortuantly it took until he was about 7 years old to find a diagnosis. It is a little more known today,then it was then, so ask your doc about it. A neurologist is who diagnosis and treats it. But they ruled out everything else with my son first, so they will probably do other tests first. My son, who is 14 now, had the scope down the throat, a CT scan to rule out brain tumor.Does your child throw up in the AM , or is it random times? Good luck
the last 3 times,it has been starting about 5-6 am. But,it continues for about 2-3 days. I will think that he is fine , because he doesn't throw up for about 6-7 hours and then he will eat something and he will throw up. It usually lasts about 2-3 days, though.
As you know it could be anything...food allergy, reflux, intestinal problems...has he seen a doctor?