Newborn Poop Colors: What's Normal and What Needs a Closer Look

The first week: a color timeline

• Days 1-2: meconium. Black or dark olive green, thick and sticky like tar. A little petroleum jelly on the skin makes it easier to wipe off.
• Days 3-4: transitional stools. Greenish brown, looser. This shift is a good sign that milk is getting through.
• Day 5 onward: mustard yellow and seedy for breast milk; tan, yellow or light brown and a bit thicker, like peanut butter, for formula. Combination-fed babies land in between.
• For how many wet and dirty diapers to expect, see the diapers guide.

Colors that are usually normal

• Yellow, mustard, orange-yellow: classic breast milk poop.
• Green: very common. It can come from fast passage through the gut, a foremilk-heavy feed, a passing virus, or iron-containing formula. A green stool in a baby who is feeding and growing well is not a worry.
• Tan or brown: typical for formula, and for all babies once solids start.
• Dark green, almost black: can happen with iron-fortified formula or iron drops.

Texture

• Breastfed stools are runny, with little curds that look like seeds. That is not diarrhea.
• Diarrhea looks different: much more watery than usual, much more often, sometimes leaking out of the diaper, or with mucus.
• A little mucus now and then, often during teething or a cold, is common.
• Hard, pebble-like stools or a dry, crumbly texture point to constipation, which is unusual in breastfed newborns.

Colors that need a closer look

• White, chalky gray, or pale clay-colored stool. This can be a sign that bile is not reaching the gut, as with biliary atresia, a rare liver condition that does far better when it is treated in the first weeks. Some hospitals hand out a stool color card for this reason. Keep the diaper or take a photo in good light.
• Red streaks or flecks. Often a tiny tear near the anus (a fissure) from straining, or swallowed blood from a cracked nipple. It can also be a sign of cow's milk protein allergy.
• Black stool after the first week, once meconium has passed and the baby isn't on iron.
• Things that can fool you: beets or red foods (once solids start), red-tinged urine crystals in the first days, and a dark green that looks black in dim light. Check in daylight.

Tips

• Take a photo of any stool you are unsure about. It saves describing it on the phone.
• Note how the baby is feeding, the number of wet diapers and whether they seem well. Those matter more than any one color.

When to check in

• Mention mucus, frequent green stools with fussiness, or a hard stool pattern at the next visit.
• Call the pediatrician the same day for white, gray or pale clay-colored stools, any blood, or black stools after the first week.
• A baby with bloody stool who is also vomiting green, very sleepy or has a swollen belly needs urgent care; if they are hard to wake, call 911.