Green Poop in Babies: 6 Common Causes (& What to Do)

Green poop in babies is normal in the first days of life. It is a result of substances that accumulated in the baby’s intestine during gestation. Green poop that emerges later on can also be caused by intestinal infections, breastfeeding, eating green food, changing milk sources or using antibiotics. 

It is important to consult a pediatrician if the green poop os accompanied by other symptoms, like fever, colic, diarrhea or changes to stool texture. These signs may additionally indicate a food intolerance or gut infection. 

When necessary, treatment for green poop may be directed by a doctor depending on the underlying cause. The doctor may advise dietary changes in the mother and/or baby, or suspension of certain medications.

Why is my baby’s poop green?

The main causes of green poop in babies are: 

1. Meconium

Meconium is the first stool that a baby passes, and is characterized by a dark green or black color that lightens over the course of a few days. It is normal for the green color to persist for up to a week after labor until it starts to turn yellow. Some babies may also pass yellow stool with green granules during this phase.

What to do: In these cases, specific treatment is not necessary. Parents are advised to continue feeding the baby as normal, as this stool color change is natural and healthy. 

2. Breastfeeding

It is normal for babies who exclusively breastfeed to have light green poop. Stool that becomes darker and has a foamy texture may be a science that the baby is just consuming foremilk, which is rich in lactose and low in fat. This can hinder normal growth. 

What to do: It is important for babies to completely empty one breast before offering the other, as hindmilk is associated with higher fat levels. Babies who fatigue easily and stop suckling should be offered the same breast they were previously on to ensure they receive all possible nutrients.

3. Changes to milk

Babies who are on formula milk will typically have darker yellow stool, however green poop may be noted with formula changes. 

What to do: Green poop is normal with formula changes and usually resolves after 3 days. In addition to green poop, babies may experience diarrhea and colic, which may be a sign of an intolerance to the new formula. If the baby presents with these symptoms, resume the previous formula and consult a pediatrician for further advice. 

4. Intestinal infection

An intestinal infection can lead to much faster flow through the intestines, leading to diarrhea. As a result, bile (a green substance that is responsible for fat digestion) is rapidly eliminated from the intestines, leading to greener stools. 

What to do: It is important to consult a pediatrician if the baby presents with liquid stools, fever or vomiting. The doctor can determine whether an infection is present and initiate treatment, which may involve oral rehydration with electrolytes. 

5. Green food

Stool color may be a sign of sensitivity to green foods consumed by the mother (if breastfeeding) or from high consumption of green solids from the baby, like spinach, broccoli and lettuce. 

What to do: Women who breastfeed should maintain a balanced diet and monitor when new or different foods are consumed, incase they cause a reaction in the baby. Babies who eat solids and are passing green stools can be treated by simply removing the amount of green foods from the diet. 

6. Antibiotic use

Antibiotic use can alter stool color by reducing intestinal flora. These are beneficial gut bacteria that also contribute to stool’s natural brown color. 

What to do: Generally, stool returns to a normal color about 3 days after terminating a medication. Green stools that persist and present with other symptoms (like abdominal pain and diarrhea) should be assessed by a pediatrician.