hello, I have twin babies, a boy and a girl. They will be one year old in a few days. They were on Nutramigen Formula, and I switched to whole milk a week ago. They have hardly pooped. My daughter poops hard pebbles, and it makes her bleed and is horribly painful. Her poop is light green/yellow. My son poops one tiny dark green pepple a day, but his is not painful. I switchd to Lactaid 100% Lactose free milk a couple of days ago, and my son has thrown up each time I ve given it to him. What can I do?