hello, my 1 year old son sometimes squeezes his legs together by tensing his hips and pushes his back into the seat. He only does it when he's sitting or lying down and wiggles about. He makes a face almost like he's in pain. Sometimes I think he's constipated or trying to pass gas but he doesn't have constipation and passes gas throughout the day as normal. I've noticed sometimes when I'm changing his nappy he squeezes his thighs together on his private parts. Would anyone out there know what's wrong? My doctor thinks it's just a habit as when you touch his stomach or private area he doesn't seem in pain.