My 5 m/o breastfed baby has been doing lots of small dark green poos for the last two weeks - one after every feed. (Before this she would do one big yellow one each day.) I read that green can mean they're drinking too much foremilk and not enough hind milk, but I don't think this is it - she has always been a fast and efficient feeder but seems to feed on each boob until empty. She seems happy and healthy in every other way. Can there be another reason?