On the other hand, if the shade of green seems abnormal and even alarming, then it might be because you baby is struggling to breakdown the abundance of lactose in the milk. (followmum.com)
Others, like lactose in milk or the sugar fructose, are digested by some but not all people. (theveganrd.com)
But if you're one of those few who do have adverse effects from lactose in milk, you'll be quite uncomfortable after consuming anything with lactose. (healthyeating.sfgate.com)