Could also be an intestinal issue, sometimes a fold of intestine sort of telescopes on itself. What kind of workups have been done? Has a barium X-ray ever been done?
Has he been taken to a pediatrician? He could have some sort of re-flux issue or allergy if he is not being breastfed. I had re-flux as a child and I vomited a lot.
wWth that kind of vomiting I am sure the child was taken to the doctor what did they say was causing it.? It sounds food related ..you say she is still vomiting each night ? is it after eating ?