The Scoop on Green Poop in Babies

As an at-home pediatrician and board certified breastfeeding medicine specialist, green poop in babies is one of the most frequent concerns I hear from my patient’s parents. In fact, I often receive text messages with pictures of a baby’s poopy diaper accompanied by the question, “is this normal?”

If you worry about the color of your baby’s poop, you are not alone. 

In this article, I will unveil the mystery of baby poop in all of its array of colors. My goal is for this information to set your mind at ease so that you don’t panic the next time you go to change your baby’s diaper. 

Reasons for Green Poop in Babies

Depending on your baby’s age, there are a variety of reasons for green poop in babies.  Young babies who are on a formula or breast milk only diet will have different reasons for poop colors than babies who are eating solid foods. 

One of the reasons why an older baby’s poop may appear green is due to their diet. Green vegetables, such as spinach or peas, can cause the poop color to change from brown to green.  Likewise, anything with green food coloring in it will change the color of your baby’s poop.  So, the next time you see green poop, think back to what your baby ate in the last day or so. 

Another factor that influences the color of a baby’s poop is the speed of their digestion. When the food moves quickly through their digestive system, bile – a substance produced by the liver – doesn’t have enough time to break down completely, resulting in greenish stools.

Moreover, viral infections can also play a role in the color change. Specific infections, like rotavirus, can cause the stool to appear green. If your child has the “stomach bug” from a viral infection, you will note particularly green poop.

Additionally, it is possible for your baby’s stool to change color if they have excessive saliva or spit from things like teething. This extra volume of saliva will mix with the food in your child’s digestive system and potentially change the color of their poop. 

Causes of Green Baby Poop in Younger Babies 

As we have already discussed, green poop in babies concerns parents. This is especially true for parents of younger babies. It may seem more mysterious to you that your baby is producing green poop when their diet is the same every day. 

Similar to older babies, younger babies who have rapid transit times of food through their digestive system will likely have green poop. Bile is a green colored enzyme that is stored in the gallbladder and secreted through the liver to digest fats. If the food moves rapidly through the system, it does not have as much time to break down the fat and can add a greenish tinge to the stool. We see this in both formula and breastfeeding babies. However, formula fed babies are more likely to have green stools 

Additionally, younger babies can have GI infections from viruses and bacteria that can change the color of their poop as well. Bacterial infections can sometimes cause bloody or black stools. If this is the case, be sure to alert your baby’s pediatrician. 

Green Poop in Newborns

When a baby is first born, we expect them to have a blackish brown poop that is sticky and is called meconium stool. This substance is made up of digested amniotic fluid, skin cells and cells from the intestinal lining that have sloughed off. A baby’s stool will then change to a dark green color and is known as transitional stool.

By five days of life, we expect both breastfeeding and formula feeding babies to have bowel movements that are yellow to brown in color. Normal color for baby poop is variable. Most often, exclusively breastfeeding babies will have mustard yellow, seedy stool by five days after birth. In addition, they should have at least 5 wet diapers per day at that age. Formula feeding babies can have an unusual color to their stool. However, generally their poop is brown to dark brown in color. 

Other possible reasons for green poop:

• Supplementing newborns with iron can have the side effect of causing green-colored stools.
• Certain medications, such as antibiotics, can result in changes in stool color.
• if a newborn undergoes phototherapy to treat jaundice, it can affect the color of their stools.

Green Poop in Breastfeeding Babies

For breastfeeding babies, green poop can sometimes be a sign of breast milk oversupply. If a breastfeeding mother produces a large volume of breast milk, the baby can get a higher load of foremilk which is rich in carbohydrates. The baby will get less hind milk which has the fat and slows things down. Green stool results from the rapid movement of this lactose rich milk through the digestive system. You may also note frothy poop or foamy poop as well.

Additionally, there may be mucus in baby poop if the baby is sensitive to cow’s milk protein. Often, a baby who is sensitive to the milk protein in a mother’s diet will also have fussiness and bloody stools as well. Milk protein allergy is different from a true milk allergy. 

Please note that foremilk/hind milk imbalance is only a problem for mothers who produce excessive amounts of breast milk. Mothers who produce physiological amounts of breast milk (I.e. 24-30 ounces per day) have breast milk that does not separate into it’s components of foremilk and hind milk as readily. 

Breastfed baby poop is generally yellow and seedy. If you notice different colored stools such as green stools or brown 

When to Worry about Green Poop in Babies

In general, green poop in babies is not something that you need to worry about.

However, if your baby is having loose stools or watery stools in addition to other symptoms such as vomiting or fever, it is best to alert your pediatrician if your baby is younger than 3 months old. If your baby is older, generally you can safely treat their symptoms at home and observe them. Be sure to keep an eye out for signs of dehydration.

Causes for Green Poop in Toddlers 

Causes for green poop in toddlers are similar to babies. Toddlers can eat green foods that cause green poops. Additionally, they are more likely to have stomach bugs because they often put everything in their mouth, including germs. They can also experience rapid transit of stool through their digestive system. Green poop, especially hard stools, can be a sign of constipation in a toddler as well. 

You can read more about why toddlers have green poop in a previous article that I wrote. 

When to call the pediatrician 

More often than not, variations in regular poop colors are normal in babies. However, there are times when you need to alert your child’s healthcare professional about the color of their poop.

Here are reasons to call your baby’s pediatrician:

• green stools accompanied by signs of infection and/or signs of dehydration
• breastfed infants with streaks of blood or mucous in their stool
• white baby poop (white stools are often causes by a lack of bile and may indicate a liver problem)
• black poop as it may be a sign of gastrointestinal bleeding 

While I can’t offer specific medical advice for your baby, I made a baby poop color chart for you so that you can understand the different reasons for color variation in your child’s bowel movements. 

© 127 Pediatrics, March 2024

This article is for informational purposes only. While Dr. Wadley is a board certified pediatrician, she is not your child’s pediatrician and cannot offer specific medical advice. Please see your child’s pediatrician for concerns about your child.