My son does every 6 weeks or so. I am thinking it may due to yellow or red food dye. I noticed that it usually happens after he has too many things with red or yellow on it. I have cut out snacks like doritos, cheetos and anything caked with a lot of seasoning. I am also cutting out boxed mac and cheese and also crystal lite. I also realized that he does that a lot on my cleaning weekends which is every 2 weeks so I am making my own cleaning products or getting ones that are environmentally friendly. Since I've been doing this, its been getting better or hes out growing whatever it is.
No one seems to know what is wrong with him and its very frustrating. Sometimes you can tell his stomach hurts and other times nothing. when he pukes every 15 mins for an hour, hes done and goes back to running around and playing like nothing ever was wrong.