Has anyone had a problem with Enfamil AR giving their baby constipation? I know it's thicker formula because of the rice but that's what he needs because he's under weight. 🙁 He's 3 months old and was pooping at least twice a day.. it's only been 24 hours from when he last pooped. I'm just getting worried. He's not acting like it's bothering him but I'm sure if he goes much longer without pooping he will start getting fussy.