Green Poop in Babies
The short answer
Green poop in babies is almost always completely normal and nothing to worry about. It can be caused by iron in formula or supplements, a foremilk-hindmilk balance in breastfeeding, dietary changes, or simply normal variation in how quickly food moves through the gut.
By Age
What to expect by age
In the first few days, your baby passes meconium, a dark greenish-black, sticky stool. This is completely normal and expected. Over the next few days, stools transition through dark green to yellow-green and then to the typical colour for your baby's feeding type. This progression is actually a reassuring sign that feeding is going well.
Breastfed babies typically have yellow, seedy stools, but occasional green stools are very common. This can happen if your baby gets more foremilk (the thinner milk at the start of a feed), if you eat certain green foods, or simply as normal variation. Formula-fed babies often have greener, more paste-like stools, especially with iron-fortified formula.
Green poop continues to be a normal variation. If your baby has started iron supplements (often recommended around 4 months for breastfed babies), dark green or greenish-black stools are a very common and harmless side effect. Illness with a tummy bug can also temporarily turn stools green.
Once your baby starts solid foods, you may see a whole rainbow of stool colours depending on what they eat. Green vegetables like peas, beans, and spinach can turn stools quite dramatically green. This is completely harmless and shows your baby is eating their greens.
As your toddler's diet expands, green stools remain a normal variation. Bright green can come from food colouring in some snacks and drinks. As long as your child is well, eating normally, and not in pain, green poop on its own is not a concern.
What Should You Do?
When to take action
- Your newborn is passing dark green transitional stools in the first week of life
- Your formula-fed baby has greenish stools, which is common with iron-fortified formula
- Your breastfed baby has occasional green stools but is feeding well and gaining weight
- Your baby started iron drops and their stools turned dark green or greenish-black
- Your baby recently started solids and has green stools after eating green vegetables
- Green stools are accompanied by mucus or a slimy texture consistently over several days
- Your breastfed baby has persistently green, frothy stools and seems unsettled after feeds, which may suggest a foremilk-hindmilk imbalance worth discussing with a lactation consultant
- Your baby has green stools alongside other symptoms like a rash, excessive fussiness, or poor weight gain, which could occasionally suggest a food sensitivity
- You see blood (red or dark streaks) mixed in with green or any colour stool
- Your baby has pale, chalky white or very light grey stools, as this can indicate a liver or bile duct issue and needs urgent medical attention
- Your baby has green watery diarrhoea many times a day and shows signs of dehydration such as fewer wet nappies, no tears, or a sunken soft spot
Sources
Related Resources
Related Digestive Concerns
My Baby's Belly Looks Swollen
A rounded, slightly protruding belly is completely normal in babies and toddlers due to immature abdominal muscles and their proportionally larger organs. However, if the belly becomes suddenly swollen, feels hard and tight, or is accompanied by pain, vomiting, or changes in bowel movements, it needs medical evaluation as it could signal gas buildup, constipation, or rarely, something more serious.
My Baby Has an Anal Fissure (Blood When Pooping)
A small streak of bright red blood on the surface of your baby's stool or on the diaper is most commonly caused by an anal fissure, which is a tiny tear in the skin around the anus from passing hard stool. Anal fissures are very common in babies and toddlers and usually heal on their own with simple measures like keeping stools soft. While this is rarely serious, any blood in your baby's stool should be mentioned to your pediatrician.
My Baby Eats Non-Food Items (Pica)
It is completely normal for babies and young toddlers to explore by putting objects in their mouths. True pica, which is the persistent eating of non-food substances, is uncommon before age two and may be linked to iron deficiency or developmental factors. If your child repeatedly seeks out and eats non-food items past the typical mouthing stage, it is worth discussing with your pediatrician.
Baby Excessive Gas After Starting Solids
Increased gas after starting solid foods is completely normal and expected. Your baby's digestive system is encountering new proteins, fibers, and sugars for the first time and needs time to adapt. The gut bacteria are also diversifying, which naturally produces more gas. This typically improves within a few weeks as the digestive system adjusts to each new food.
My Baby Gulps Air While Feeding
Swallowing some air during feeding is normal for all babies, but excessive air gulping can lead to gas, hiccups, and spit-up. Common causes include fast milk flow, poor latch (if breastfeeding), bottle nipple flow that's too fast or slow, and crying before feeds. Simple adjustments to feeding position, pacing, and equipment can usually help reduce air intake significantly.
Baby Poop Color Changes with Solids
Dramatic changes in poop color after starting solids are completely normal and expected. What your baby eats directly affects stool color - carrots may turn poop orange, spinach makes it green, beets can make it reddish, and blueberries can turn it dark blue-black. As long as your baby is comfortable and the stool is not white, black (tarry), or bright red with blood, these color changes are harmless.