My two year throws up at night only what can it be because throughout the day he is fine he is running and playing around and he eats perfectly fine. Even when he naps he is okay but when it comes to the night when he is in bed that is when it starts that he throws up a lot then when he is finish he goes back to bed and then he is fine. He doesn’t throw up at all only once but I have noticed that when he is sleeping when he farts they are really stinky. What can it mean?