Jun 10, 2024
June 10, 2024

What to do when your baby has diarrhea

Dealing with diarrhea is never pleasant – it can be messy, incredibly uncomfortable, and can lead to painful diaper rash if it's not managed. It can also be tough to tell the difference between soft, loose baby poop and diarrhea. We'll break down everything you need to know about newborn diarrhea, how to recognize it, how it differs from normal poop, and what to do if your baby is experiencing it.
Dahlia Rimmon, RDN
Written by
Dahlia Rimmon, RDN
Content Writer
Dr. Marcy Borieux
Medically reviewed by
Dr. Marcy Borieux

Normal newborn baby poop consistencies

While some infants have loose, soft stools, others may pass more formed and pasty poops. These differences are often linked to whether the baby is breastfed or formula-fed. Here are a few examples of normal poop textures and consistencies:

  • Soft and runny

  • Mushy

  • Seedy

  • Pasty

  • Formed

If your baby suddenly has very watery stools, or more frequent stools (three or more stools per day), it could be a sign of diarrhea. On the other hand, if your baby consistently passes hard, pellet-like poops, it can indicate constipation.

Keep in mind that during the first two weeks of life, newborns will sometimes pass stools frequently, which is perfectly normal.

Signs of newborn diarrhea

These are the most common signs of newborn diarrhea, and will give you an idea of what your baby's poop might look like if they have diarrhea:

  • Watery, loose stools

  • Foul smell

  • May contain mucus or blood

  • Frequent stools

Causes of newborn diarrhea

The reasons a newborn may have diarrhea include:

  • Viral infections

  • Bacterial infections

  • Antibiotic-associated diarrhea

  • Cow’s milk allergy

  • Change in diet

Symptoms of diarrhea and dehydration in newborns

Diarrhea can also cause your baby to become dehydrated. Watch out for these signs of dehydration:

  • Fewer than six wet diapers per day

  • Parched lips or dry mouth

  • No tears when they cry

  • Unusual sleepiness

  • Sunken soft spot on the top of their head

Dehydration can be serious in newborns, so it's important to encourage your baby to continue drinking breast milk or formula to restore the fluids leaving their body through diarrhea.

Diarrhea in newborns who drink breast milk vs. infant formula

While there is a difference in normal stools between breastfed and formula-fed newborns, there is no difference in their diarrhea. A reminder that normally, poop in yellow and seedy in breastfed babies. In formula-fed babies, poop is normally yellow, green, or brown.

What to do if your baby has watery stools and diarrhea

If you suspect your baby has diarrhea, it’s important to address and treat it promptly. Remember: Diarrhea can lead to dehydration, which is particularly risky for babies, especially for babies under 3 months. Making sure your baby stays hydrated is the most important thing to do if your baby has diarrhea.

When babies have diarrhea, they can lose a lot of fluids, so it's essential to encourage feeding even if they seem fussy. While you shouldn't force it, try to encourage your baby to nurse, or drink breast milk or infant formula from their bottle.

When to contact a pediatrician

Baby’s can get dehydrated pretty quickly so if you notice any symptoms, whether mild or severe diarrhea, contact your local pediatrician or a Summer Health pediatrician to see if an oral rehydration solution, like Pedialyte, is an appropriate option for your baby.  


Healthy Children: Diarrhea (0-12 months)

American Academy of Pediatrics (AAP): Signs of Dehydration in Infants and Children

Dahlia Rimmon, RDN
Content Writer
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