Breastfeeding Poop vs. Formula Poop. What's the Difference?


In the first few years after having a baby, many parents begin to notice the varying differences of the stool in their baby’s diaper. The good news is many of these variations mean your baby is healthy and growing. However, others may indicate there’s a problem and should be discussed with your baby’s doctor. Differences in consistency and color have a lot to do with what’s being consumed by your little one, such as whether they’re being breastfed or formula-fed. Erin Gholson, ARNP, UnityPoint Health, explains the different types of baby poop, including breast milk poop vs formula poop.

Normal Bowel Movements for Breastfed Babies

Many parents have concerns about the different types of bowel movements and what they mean for their baby. Within the first few days after birth, a baby’s bowel movements will consist of meconium, which is the thick, black or dark green substance that was held in their intestines before they were born.

When baby is about three days old, the stool changes into a green color. The stool becomes less sticky and easier to wipe off. As your milk supply increases, the bowel movements turn yellow and seedy. As long as your baby is getting only breast milk, the stool may have a sweeter smell. If formula is introduced, or when foods are started, parents may notice the poop has a stronger odor and, the appearance changes in color and consistency.

Abnormal Bowel Movements for Breastfed Babies 

If your baby has a change in their typical bowel movement patterns, it’s recommended to discuss it with their provider. You could also consider a feeding assessment with a lactation consultant. There are several reasons why a baby’s stool may change, such as adjustments to the baby’s feeding patterns. Mom’s diet can also influence bowel movements. In some cases, changes may indicate food sensitivities or illness.

Normal Bowel Movements for a Formula-Fed Baby

All newborns, regardless of feeding method, will first pass meconium. Once that passes, the bowel movements of a formula-fed baby typically consist of yellow or tan stool. Green stools are also common. Formula-fed babies' bowel movements are normally a bit firmer than those who are breastfed. Many parents find the consistency similar to peanut butter.

Abnormal Bowel Movements for a Formula Fed Baby

Along with knowing what to look for in normal bowel movements, understanding abnormal stool signs is crucial as well. If you notice the consistency is harder than that of peanut butter, this could be a sign of constipation. If this is the case, contact your baby’s doctor. If you’re worried about possible constipation, and your baby is younger than 4 months old, avoid giving them anything other than breast milk or formula without consulting your baby’s provider first.

Frequency of Bowel Movements

During the first three months after being born, it’s normal for babies to have multiple bowel movements each day. Breastfed babies have an average of three bowel movements per day. It can also be normal for a breastfed baby to have a stool after each feeding or as little as once every seven days. Formula-fed babies have an average of two bowel movements per day. After the first three months, it’s normal for bowel movement frequency to decrease. It’s important to know that baby is still growing well as bowel movement frequency changes.

If you ever have any concerns, please discuss them with your baby’s doctor.

When to See Your Doctor About Your Baby’s Bowel Movements

Our providers want to make sure you and your loved ones understand the full range of “normal” baby poop. Many of these variations mean your baby is healthy and growing. However, other variations are concerning and may indicate a problem. If your baby has red/bloody stools; black, tarry stools or white stools, contact your baby’s doctor right away. You should also seek care if bowel movements are especially watery, dry, hard or difficult to pass.