<p>I've been avoiding dairy with my newborn (he's 3.5 weeks old) but "trialed" it today. I'm wondering how long it takes for the dairy protein to show up in my BM and affect him, if it's going to.</p>
I think it really depends on the speed of your digestion, so I would say between an hour - 24 hours. And if your LO only has digestive issues (rather than skin issues, etc), they might take another 24 hours beyond that to start showing symptoms. Usually it's within 12-24 hours though, in our experience.