Please post your question as its own post because this one is so old. I think I might have an idea of what your son has.
My son is now 11, and has had chronic vomiting since he was 3. Usually it is after he eats and is made worse by activity. At least once a week he's sent home from school. We have had every blood test imaginable, he had a colonoscopy, and endoscopy all with normal results. They also did an esophagus, bowel and stomach biopsy while he was under. We are still baffled by his illness. He has no food allergies, no physical abnormalities and yet he throws up every day. The older he's getting the worse it's getting and we're still searching for an answer. When he throws up it is usually just there, no gag reflux or anything just has a mouth full of vomit. I hope that you are able to find an answer for your son soon. From experience I can tell you it's very frustrating to see this condition persist for so long and be unable to do anything to help your child. Best of luck!!
My two year old nephew has the same thing. He is currently waiting to have an endoscopy. Has anyone had a diagnosis of a genetic abnormality? My nephew is adopted and the doctors still think that might hold a link. Has anyone ever have this as a child in your families? We live in Illinois and he's already been to a pediatric GI specialist. He didn't seem to have this problem until about 18 months old. As a baby no vomiting issues at all. Is that the same for you all too?
I saw your comment about the boy that is constantly vomiting. This is a lot like my son. I've checked the symptoms for celiac disease and he doesn't have any of those. Sometimes the food will be undigested. Do you have any ideas about this?
This sounds just like my son. He is two and a half and throws up just about every day. Sometimes 3 or more times a day. Whenever he runs too much or coughs. I thought maybe he was allergic to milk, but I've tried keeping him off dairy and it doesn't seem like this is from food. I've looked up celiac disease and he doesn't have any of those symptoms. Please let me know if you find anything out.
An endoscopy would definatley tell if there is any damage to his esophagus or stomach.
Is there any undigested food with the puke or blood? Also has he been tested for celiac disease?