My DS is eight, and for a long time now (4 years, maybe 5? can't remember) we have noticed that when we go out to a big social event, he often vomits in the night afterwards. Typical scenarios would be a barbecue at a friend's house, or a big day out with friends. At first I put it down to the fact that he was probably overeating horribly at parties while we weren't looking. Then I thought it might be the travel or overexcitement. However, it happens even when (as yesterday!) he hasn't really eaten a great deal, and yet it doesn't happen when he goes to his grandma's house and has a big lunch plus two puddings. Also it doesn't happen when he's been to friend's birthday parties. As for the travel, he's never actually travelsick, and it doesn't happen only when he's travelled long distances. That leaves overexcitement - but he doesn't throw up at the time, only during the night afterwards, usually several hours after we've got home. Has anyone else experienced anything like this? I've no reason to suppose that it's food poisoning, as neither DH nor DD nor I get sick when he does. Is it possible that it happens because he's overtired and sleeps very deeply and ... ???? Usually it happens once in the night, but sometimes twice. Would be grateful for any enlightenment so we could try to prevent it.