Re: Green poop...confused
If you got to almost 7 months without morticing a green poop, I think the most likely explanation for the green poop at this point is the formula, which will turn a kid's stool a kind of olive green color. However, solids could also explain the color change- even small amounts will result in color changes. And more watery milk from spaced-out pumping sessions could also explain the change.
Please don't let green poop freak you out. Green poop is only an indicator of a health problem if it's accompanied by additional worrisome symptoms, like poor growth, severe discomfort or fussiness, or signs of allergy (blood in the stool, rash, excema, asthma, etc.).
Seriously, this is nothing to freak out about, and I absolutely would not dump your precious milk or go exclusively to formula over this!