Hi, I am new to the forums and new to pumping and could use some help trouble-shooting a problem I'm having. I think I may have an oversupply issue. My son Joshua is 14 weeks old, and I went back to work 2 weeks ago. Ever since I went back to work, he's been having consistently green poop. Sometimes it is bright green and watery, other times darker green with curds in it. He hasn't been as gassy as he was as a young baby, but does cry when he's trying to poop (he has always done this though). He's otherwise generally a happy baby, content, gaining weight beautifully, around the 40th-50th percentile for both length and weight. I had definite oversupply early on, when my son was 4-6 weeks old. He was fussy, very gassy, and usually had green stools. I'd been following incorrect advice about switching breasts every 5-10 minutes when feeding and when I stopped doing that and started keeping him on one breast until he drained it, the problem went away and his stools were back to the yellow, mustard seed type (most of the time; sometimes a darker brown-green with curds in it). I'm not sure why suddenly he is now back to having green stools now.
I pump twice per day usually, for about 30-40 minutes at a time (I have always done longer pumping sessions) and I am gone about 6-7 hours per day. I usually get 9-12 oz with my first pumping session and 4-6 oz with my second, for an average of about 15-16 oz/day. He normally drinks 7-10 oz while I am gone, so I am making a bit more than I need, but not that much more when you account for the fact that several ounces usually get wasted per day because he doesn't always finish his bottle. I was really worried when I first went back to work that I would have problems making enough for him, but luckily so far that hasn't been the case. My concern now is that by pumping so much and for so long I am making oversupply worse and causing foremilk/hindmilk imbalance and this might be the reason for the constantly green poops. However, I am afraid to cut back on pumping in case this causes me not to have enough milk.
I have been looking into causes of green poop other than oversupply and one thing that comes up is that teething can cause it. Joshua definitely seems to be teething right now as he has been drooling non-stop for the past several weeks. No actual teeth yet though.
Does this sound like an oversupply issue? If so, how do I change my pumping pattern to help with that, while still making sure to pump enough milk? Any suggestions or ideas from experienced moms who have been through this? Thanks in advance!