Why Does My Baby's Poop Smell Sour?


Babies are a bundle of joy, but taking care of them can be overwhelming. One of the things that parents often worry about is their baby’s poop. New parents may find it difficult to understand what is normal and what is not. In this article, we will discuss why your baby’s poop smells sour and what you can do about it.

What Causes Sour-Smelling Poop?

The smell of poop is determined by the food your baby eats, their digestive system, and the bacteria in their gut. If your baby’s poop smells sour, it could be due to a few reasons:

  • Change in diet: If you have recently changed your baby’s diet, it may take some time for their digestive system to adjust.
  • Dehydration: When your baby is not getting enough fluids, their poop can become hard and difficult to pass, leading to a sour smell.
  • Infection: Certain infections like gastroenteritis or a yeast infection can cause a sour smell in poop.
  • Medication: Some medications can affect the smell of poop, including antibiotics.

What Does Normal Poop Smell Like?

Before we dive deeper, it’s essential to understand what normal poop smells like. Breastfed babies’ poop usually has a slightly sweet smell, while formula-fed babies’ poop can have a more pungent smell. However, this can vary from baby to baby.

When Should You Be Concerned About Your Baby’s Poop?

If your baby’s poop smells sour occasionally, there may not be anything to worry about. However, if the sour smell persists or is accompanied by other symptoms like diarrhea, vomiting, or fever, it’s time to call your pediatrician.

How Can You Help Your Baby?

Here are some tips that can help:

  • Offer more fluids: Make sure your baby is getting enough fluids to prevent dehydration.
  • Check their diet: If you have recently introduced new foods, try eliminating them to see if the smell improves.
  • Probiotics: Probiotics can help balance the bacteria in your baby’s gut, which can improve the smell of their poop.
  • Change formula: If your baby is formula-fed, try switching to a different brand to see if the smell improves.


In conclusion, a sour-smelling poop may not be a cause for alarm, but it’s always best to keep an eye on your baby’s overall health. By following the tips mentioned above and consulting with your pediatrician, you can help your baby feel better and improve the smell of their poop.