Yes, he has had blood work done and a stool sample done as well. Everything came back normal. No, I have never heard abdominal migraines. I'll check to see if my don has any of those symptoms.Thanks.
Seeing an allergist will be good to rule out any food allergies. Have any of the docs checked bloodwork or stool samples for parasites? Have you ever heard of "abdominal migraines"? Check out the symptoms and see if they are familiar to what your son is experiencing. Though any major medical problems/issues should be ruled out first.
Ive heard of testing for wheat, milk, soy etc. but never heard about the parasite. Would that cause him to vomit once a month?
He doesnt complain about his head during vomiting, but if you to talk to loud, and we tend to be a loud family, he says he feels like he has a headache.
Does he have headaches with the vomiting?
It could be a food allergy that is bothering him and since you are going to an allergist I recommend testing many of the common allergens along with some other things that you eat often. Test for soybean, wheat, milk, nuts, etc. It could also be a parasite of some kind so if he shows up negative for food allergies, you could try a parasite stool test.