Baby's First Poops: What to Expect

There are many “firsts” to look forward to with the arrival of your new child, and poop is one of them! A baby’s first poop is distinct from all subsequent poops, which means there are some important things to know about it.

What is the First Poop Called?

The first poop your baby passes is called meconium. It is thick, sticky, and black or greenish-black in color. The distinct color is due to bile, which is produced in the liver and helps with digestion. It is sterile and odorless because there are no bacteria colonizing your baby’s intestines before birth. After birth, as soon as feeding begins, bacteria colonize the intestines and subsequent poops are no longer sterile or odorless.

When Should Baby's First Poop Happen?

The passage of meconium should occur within the first 48 hours after birth. Most babies pass meconium within the first 24 hours. Some babies will pass meconium prior to birth while inside the womb. Passage of meconium by the baby into the amniotic fluid changes the color of the fluid from clear to various shades of green. Passage of meconium during the laboring process could be a natural event or it could indicate fetal stress. If this occurs, the baby could aspirate the meconium into his or her lungs. Aspiration of meconium into the lungs of the fetus could cause breathing problems after birth. If meconium passage does not occur within 24-48 hours after birth, your physician will look for intestinal problems that could be causing the delay.

What Happens After the Meconium?

Following the passage of meconium, subsequent stools may continue to be thick and tarry for a day or two. Eventually stools change in consistency and color and are called transitional stools. These stools are lighter in color than meconium. Finally, by the end of the first week, the baby’s stools will look seedy and pasty in texture and mustard yellow in color if breast fed. Babies that are fed formula tend to have browner colored stools that have a consistency like peanut butter.

Reach out to a CHI Health Maternity provider for more questions.

Written in collaboration with medical student, Sarah Craven.