My 4.5 month old DD has been grunting, getting red in the face, crying out and looking like she needs to poop. She seems like she could be in pain, but she also smiles in the middle of all this. She has been pooping pretty normally, maybe a little "thicker," but not terribly thick or hard. Should I be concerned? If I should, do I give her prune juice? water? let it be? Thanks moms!