Hello girls, I'm writing and I don't even know anymore, my baby is 3 months old, we fully switched to formula around 2 months, and with any formula, my baby has green or dark green stool, like swamp water. His belly is soft and doesn't really bother him much. We are now switching from Nan Triple Comfort to regular Nestogen. I've heard that even iron can turn the stool green (Nan had 15 iron, while Nestogen has 5).