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Mom’s Question:

Is it really normal with runny poop in a breastfed baby? My daughter is 8 weeks old and fully breastfed. Ever since she was born, her poop stays watery. Is this normal? There is no consistency in her stool. Once in a great while, there is.


Baby Helpline:

Watery, Runny Poop Normal Or Not For Infant?

Normal Runny Poop in a Breastfed Baby

What you describe is probably normal runny poop in a breastfed baby. Breast milk poop is usually yellow and quite runny.

The older the fully breastfed baby the more poop, and in my experience, with the increasing amount, the poop appears to be even runnier although it probably isn’t.

At around 2 months, many breastfed babies have enough runny poop to shoot up all the way to the back of their neck if you are unlucky!

The poop may also be like mustard or yellow yogurt and has some texture in it, be curdled or seedy. It varies from child to child and over time.

If your daughter is happy and follows her growth curves, everything is likely to be fine. But if your baby seems to be in pain, if there is mucus in the poop or she is not gaining weight, you might want to discuss it with a pediatrician.

Runny Poop in Babies – Not Normal

But then, when is runny poop in breastfed baby a sign that something is not right?

Well, even if runny poop in breastfed babies is considered normal, there are, of course, situations when it is not.

Diarrhea due to a stomach bug or a cold

If a baby’s stools suddenly increase sharply or become much more watery, it may be that the baby has diarrhea due to some stomach bug or a cold.

Other signs, in such a case, would be that the baby has a fever, poor appetite, or simply appears to be ill.

Find more symptoms of diarrhea here.

Diarrhea due to Milk Protein Allergy

Even though you breastfeed, it is possible that your baby is having watery stools due to milk protein allergy.

This is because the milk protein is be passed over to the baby through breastmilk.

Some of the signs that your baby has milk protein allergy are:

  • Crying a lot
  • Discomfort after feeding
  • Restless sleep
  • Diarrhea, or constipation
  • Cold-like symptoms, wheezing
  • Itchy, red eyes
  • Dry skin or a diaper rash

Diarrhea in Breastfed Babies – Rare Reasons

There are other, often more severe, but also rare reasons why a baby may have diarrhea for a long period of time.  These are not something to be particularly worried about, but to be aware of, if your baby isn’t growing, appears ill or is not hitting her milestones.

Chronic diarrhea can have many causes, including:

  • Bacterial or parasitic infection –  rare in developed countries. Where do you live?
  • Chronic inflammation of the digestive tract, such as ulcerative colitis or Crohn’s disease
  • Chronic, nonspecific diarrhea of childhood — a condition that usually occurs in children ages 1 to 3, so your daughter is most likely too young for this
  • Irritable bowel syndrome
  • Tumors in the digestive tract
  • Hirschsprung’s disease — a condition that results from missing nerve cells in the muscles of part or all of the baby’s colon.
  • Cystic fibrosis
  • Zinc deficiency – in some cases, the transfer of zink through the breastmilk is impaired. One of the symptoms is diarrhea.

Now, this was a long list of possible concerns, but again, if your baby is happy, thriving, and reaches her milestones, the most likely explanation to her runny poop is that it is simply normal!

Hope this helps,


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This Post Has 4 Comments

  1. Avatar

    My daughter has had runny poop from the day she was born. I have told my doctor on several occasions but they don’t seem to have much concern about it. It still concerns me she’s 14 months now and still had runny poop even though she eats table food. What could cause that?

    1. Paula @ EasyBabyLife

      Hi Lupita,
      Since your baby is now over a year and eating solid foods, I find it a bit strange that her doctor isn’t following up her runny poop.

      Have you been discussing food intolerance at all? Lactose intolerance, for example, can have this effect. You can always try to exclude any milk sugar (lactose) from her diet and see if it helps.
      Best regards,

  2. Avatar
    Still runny

    My 9-month-old has never gone 2 the poop normal. it’s always been watery. She’s on solid food from 4 months and nothing still hasn’t changed

  3. Avatar

    I had the same concern with my baby. The doctor said to expect runny stools until the baby is on a diet of solid foods.