My Grandson Is 6 And Very Healthy And Well-adjusted. Last

My grandson is 6 and very healthy and well-adjusted. Last year (Kindergarten age) he began vomiting repeatedly in school and at home. Not projectile, but enough to fill his mouth. He is so accustomed to it he doesn't even report it. He just spits it out into a garbage can and goes back to playing or whatever. His teachers report he will vomit 6 or 8 times a day. No rhyme or reason - he has been dairy-free since the first doctor visit. It happens after activity as well as after quiet times. No spicy or acidic foods in his diet since age 5 either. We have a rural health clinic where the doctor has put him on more acid reflux medicine. So far, they are calling it reflux, but he complains of no heartburn or pain whatsoever. Bowels normal. I think we should be considering something else. I wonder if he might not have a constriction of some sort, or maybe a hernia. Maybe a pediatric GI doctor is in order. Can you advise?