We are exclusively formula feeding now, for about the last week (long story -- let's just say BFing didn't work out and my supply pretty much vanished). We started off at 50% BM and 50% formula and slowly worked up to all formula, which she hasn't had a problem with. Since Tuesday, though, all of her poops have been very, very watery, and pretty much every poop is a blowout. She's acting fine, though -- is this something to worry about?
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Re: Very runny poops?
I had the same experience with TJ when transitioning to formula. I think it's just a newborn "thing", FF or BF. His poops even still looked like a BF baby's poop for several weeks before turning GI Joe Formula Green!
But, you can always call the pedi's office and ask (they have a nurse, right?) if you're unsure!