Thanks M.B.G. from Utah for your question about what is normal baby poop.

There isn’t a day that goes by that I don’t field a question about whether or not a baby’s poop is “normal.” The reality is that baby’s stool is changing constantly, so it’s hard to know what is normal and what to worry about.

The Normal Transition

When a baby is born, his/her gut isn’t colonized with bacteria. Bacteria are required to digest food. So, the first few stools are sticky, tar-like, and black. As an infant eats breast milk or formula, the gut will get colonized and the stool will “transition.” The stool will change from tar-like and black to greenish/brown and finally end at yellow and seedy. How quick this happens depends on each individual infant’s gut and the amount of food (breast milk or formula) the infant is eating. Most infants transition in 2-5 days.

The Poop Rules

After the initial transition, each baby’s poop will vary quite a bit. Over time I have developed what I call the “Poop Rules.” These are rules of my own creation which essentially help parents decide what is normal (no big deal, don’t worry) vs. something could be wrong (your baby needs to be seen).

  • Color. When your baby is first born, the stool will be black. After the stool has changed from black to another color, it should NEVER go back to black. The poop should also NEVER be red (like blood) or white (that means another medical problem altogether). Bottom line, as long as the poop isn’t black, red, or white, another color is acceptable. The most common colors are yellow, brown, orange, and green.
  • Consistency. Normal baby poop is anything from pretty watery with a few particles (like seeds) to thick mush or paste. You have a problem if your baby’s poop is straight liquid (like pee) or hard like a rabbit pellet/marble.
  • Frequency. Babies poop at all sorts of intervals. Some poop every time you feed them, while others go once every few days. The American Academy of Pediatrics says that it’s normal for a baby to go up to five days between stools. Personally, I think five days between pooping is a long time and tend to use the three- or four-day rule. Anecdotally, it seems that breastfed infants tend to go more frequently than formula fed infants (I think it has to do with the fact that breast milk is easier to digest than formula). So, as long as your infant’s stools fall into the “Poop Rules” norms, then you can breathe a sigh of relief and stop worrying. If, however, your baby’s poop doesn’t meet all three areas of normal, then you need to make an appointment to see your pediatrician.

Diet Changes

It is also worth noting that every time you make a change to your baby’s diet (e.g., go from breast milk to formula or start solids) that it is common for your baby’s stool to change. You can get temporary diarrhea or constipation. Generally, it is a good idea to allow your baby’s system to work it out. If however, you find that your baby starts to get outside of the “Poop Rules,” you may want to consult with your pediatrician about ways you can help your baby make the diet transition.