Reflux???

mundayem

My LO is 3.5 weeks and every time we try to lay him down on his back to sleep he is not happy. He only stays asleep for a short time, he gets fussy, and he spits up. He doesn't do this when he is on his side or his stomach only when on his back. He does when flat on his back and when he is in his napper and the swing. Does this sound like he has reflux or just that he doesn't like to sleep on his back? Any advice of suggestions to how we can get him to sleep better on his back? TIA!