In the first week of life, your baby's poop changes color several times - and that's completely normal. It usually moves from black, to greenish-brown, to yellow as their digestive system gets going. Most colors you'll see are nothing to worry about. A few specific ones are worth a call to your pediatrician.
Note: This is general information, not medical advice. If you're ever unsure about your baby's stool, call your pediatrician - they can look at it or ask you to describe it directly.
The First Poop: Meconium
The very first stool, usually in the first 24 to 48 hours, is called meconium. It's thick, sticky, and black or dark green - almost like tar. This is completely normal. It's made up of everything your baby swallowed in the womb, and it clears out within the first couple of days.
How Poop Color Changes Through the First Week
| Day | Typical color |
|---|---|
| Day 1–2 | Black, tarry (meconium) |
| Day 3–4 | Dark green to greenish-brown |
| Day 5+ | Yellow, mustard, or light brown |
Breastfed babies often have looser, seedy, mustard-yellow stools. Formula-fed babies tend to have firmer, tan or brown stools. Both patterns are normal.
Colors That Are Normal
- Yellow or mustard, seedy in texture (very common in breastfed babies)
- Tan or light brown, more paste-like (common in formula-fed babies)
- Green, especially if your baby recently had a feed with a lot of foremilk, or is on iron supplements
Colors That Need a Call to Your Pediatrician
Call your pediatrician if you see: white, pale, or clay-colored stool (can signal a liver or bile duct problem); red or bloody stool; or black, tarry stool after the first couple of days (once meconium has already passed). These colors are uncommon and worth checking promptly, even if your baby otherwise seems fine.
Why Logging Diaper Changes Helps
It's easy to lose track of what "normal" has looked like for your baby over the last few days, especially when you're exhausted and everyone in the house is taking turns with changes. A shared log means you don't have to rely on memory - or on whoever happened to notice.
Frequently Asked Questions
What color is normal newborn poop?
Yellow, mustard, green, or tan/brown are all normal after the first week. The very first stool (meconium) is black and tarry.
What color baby poop is dangerous?
White, pale, or clay-colored stool, red or bloody stool, and black tarry stool after the first couple of days are all reasons to call your pediatrician promptly.
Is green poop normal in newborns?
Yes, occasional green stool is common, especially with certain feeding patterns or iron supplements.
Sources
This guide was fact-checked against the following guidance on July 14, 2026:
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