During the first few months of life, breastfed babies typically pass stool several times per day. Their stool will also be a soft-to-runny consistency, and mustard yellow in color.

It’s important to monitor your baby’s diapers during this period, including checking the color, texture, and frequency of their bowel movements. These are good indicators that they’re getting enough breast milk. This is one way you can monitor their health in between visits to the pediatrician.

Read on to learn what to expect from your breastfed baby’s stool, and when to talk to a doctor or lactation consultant.

Over the first few days of life, breastfed babies will pass meconium. This will be tar-like in color and consistency. After around 48 hours, the stool may become looser and lighter in color. Then, within another day or two, the color of breastfed baby stool is usually mustard yellow or yellow-green. It may also be watery or contain mini-white “seeds.” This color is normal.

As your baby grows and starts solid foods, you may notice changes to the color of their stool. It may be more greenish-yellow or tan-brown in color.

Always let your pediatrician know if your baby has stool that is:

  • red
  • bloody
  • black
  • pale-grey or white

This may or may not be a sign of illness. Your doctor will be able to evaluate your baby and give you peace of mind.

Expect your breastfed infant’s stool to be soft to runny in texture. It may also be watery, almost like the consistency of diarrhea.

The texture may resemble mustard and contain small, white seed-like particles.

Each bowel movement should be about the size of a United States quarter (2.5 centimeters or larger.)

If your breastfed baby is passing hard, dry, or infrequent stools, they may be constipated. However, constipation is very uncommon, if not rare, in breastfed infants who are well. If your baby is just having infrequent stools, especially after 6-weeks old, it’s likely normal. On the other hand, if your baby has hard, dry stools along with the symptoms listed below, they’re most likely ill, rather than constipated:

  • vomiting
  • having a dry mouth
  • not wanting to breastfeed
  • being fussier than usual

Seek immediate medical care for these symptoms.

Your infant’s stool may not have a smell for the first few days. After they pass meconium, many parents claim their breastfed infant’s poop still doesn’t smell very foul.

In fact, it may smell slightly sweet or have a smell resembling popcorn. Other parents have reported their infant’s stool smells like hay or porridge.

Usually, as long as your baby is having frequent bowel movements and their stool is soft, the smell isn’t a concern.

Let your pediatrician know if you notice loose, green stools, or a smell you’re worried about. Your baby may have an allergy or intolerance to something in your diet.

Breastfed babies have frequent bowel movements. Expect at least three bowel movements each day for the first 6 weeks.

Some breastfed babies have 4 to 12 bowel movements per day. Your baby may also pass stool after each feeding.

If your breastfed baby is having less than three bowel movements a day, they might not be getting enough milk. Your pediatrician will be able to check if they’re gaining enough weight. If they’re gaining weight, having fewer bowel movements generally isn’t a problem.

After 6 weeks of age, some breastfed infants will poop less frequently. Some babies have only one bowel movement a day, while others only pass stool every other day or every few days. If it’s been several days since their last bowel movement, it will likely be very large.

If your baby is happy, feeding, and appears to be gaining weight, having less frequent bowel movements after 6 weeks of age isn’t anything to be concerned about, but let your pediatrician know if you’re worried about the frequency of your infant’s stools.

You may notice changes to your infant’s stool anytime there’s a change to their diet, such as when they start eating solid foods. If your baby switches from breast milk to formula or vice versa, you’ll also notice a difference in the color and texture of their stool.

Formula-fed infants typically have a more solid stool and it may be more yellow-green or tan in color.

Some weight loss (5 to 7 percent) is normal in breastfed babies during the first few days of life. Most breastfed babies regain their birth weight after 10 to 14 days.

If your baby is gaining weight steadily after returning to their birth weight, they’re likely getting enough to eat. Steady weight gain means that they’re gaining weight most weeks.

Let your pediatrician know if:

  • Your baby isn’t gaining weight. Their pediatrician may recommend working with a lactation consultant to confirm your baby is latching properly and getting enough breast milk.
  • Your baby isn’t feeding well or passing stool, or they’re passing hard stools. These may be signs of constipation or illness.
  • Your baby is passing black, bloody, or green frothy stools. These may be symptoms of an illness.
  • Your baby’s poop is unusually watery and more frequent. This may be a sign of diarrhea.

Over the first months of your baby’s life, it’s important to monitor their diapers carefully. Checking their poop’s texture and color is a good way to confirm your baby is healthy and getting enough breast milk.

Usually, a slight change in color or texture isn’t anything to worry about. That’s especially true if your baby has recently switched to solid food, formula, or was sick with a cold.

Let your pediatrician know if you notice any blood or black stools in your baby’s diaper, or have other concerns. Your baby’s doctor may also ask about their diapers at your well-baby checkup appointments.