Mine is. I've never really worried too much as it seems to be just one of those things and I hope he will grow out of it - but anything can set him off, like running about too much, laughing, and especially coughing.
He has a cough at the moment andisn't ill otherwise, just seems to cough a lot when he first goes to bed - just now he was a bit sick but is asleep and has stopped coughing.
I get really anxious that each time he has a coughing fit he is going to chuck all over the bed/me/his brother! It's stopping me sleeping (emetophobe) and I just started to wonder if it is normal to be so easily sick?
He is nearly 5 by the way.
I've never been like that - very rarely throw up. He's a strange child