Newborn Poop Transition: What to Expect! 💩 Your baby’s poop will go through some big changes in their first week! It starts as meconium—a thick, sticky, dark green poop that was in their bowels before birth. 🌿 👉 Over the first few poops, it will lighten to a greenish color. 👉 Then, depending on how they’re fed, it will change to: ✅ Mustard yellow with seedy texture (if breastfed) 🍼 ✅ Pale yellow and smoother (if formula-fed) 💬 How long did it take your newborn to transition from meconium?