Son Had Spontaneous Vomiting After Drinking A Lot Of Milk

Son had spontaneous vomiting after drinking a lot of milk a week ago. Fine the rest of the day. Spontaneous vomiting again the next morning after yogurt. One bowel movement of diarrhea the second day. Held off on all dairy for a day. Was fine. Never acted like anything was wrong during any of this. Solid light green stool for a few days. This morning his stool was solid but white. Has never been a great eater but I'd say slightly less eating than normal for him over the past week, ate much better today. Should I be concerned?