You know, honestly, I wouldn't sweat it. I think if he's happy and cheerful and not miserable and fussing, there's no "real problem" with foamy green poops, you know? A while back someone linked (I think it was Mommal?) to a site that basically says lots of different colors of baby poop can be "normal." My sense is that a lot more than foremilk imbalance can cause green poop. That's why I was careful to say that in my original response. I DO think that halfway pumping is not the best ... but I also wouldn't panic about some green poo. Joe's poop started to change - it became smellier and darker in color - around five months, before we introduced solids. We think it was teething-related, but who knows? What I know is that he was thriving, growing, and generally happy and not ill, so I figured, why stress?