The 411 on Baby Poop - Infant Bowel Movements

By JustMommies staff

You wouldn’t think there was that much interest in baby poo, but it seems new moms and experienced moms alike want to know more about baby poop. Your baby’s first bowel movement will be black or greenish black and look like tar. It will be really sticky too. This is called meconium.

Your baby’s first poop - meconium

During your pregnancy your baby’s digestive system starts to work by swallowing amniotic fluid. Meconium, which is made up of amniotic fluid, bile, and shed skin cells, begins to collect in your baby’s intestines while he is in your womb.

When your baby has his first bowel movement, he will empty the meconium that has been collecting. Most babies start to pass meconium within 12 hours of their birth. Not passing meconium during the first 24 hours can be a sign of a complication such as an intestinal obstruction. Occasionally, babies have their first bowel movement in utero. This can happen if baby is in distress. Furthermore, passing meconium into the amniotic fluid can cause a complication known as meconium aspiration syndrome.

The first month of baby poops - what to expect

Once your baby passes the meconium out of his system, his poop will begin to change colors. If you are breastfeeding, your baby’s stools will be mustard colored, seedy, and runny. If you are formula feeding, they will be tan colored and soft. Formula-fed babies’ stools are firmer than breastfed babies but they should not be any firmer than a peanut butter consistency. Some moms say that a breastfed baby’s poop doesn’t stink. It has a distinct smell that some describe as sweet but it still has an odor.

Babies that poop a lot

If your baby is breastfed expect a lot of poop, at least in the beginning. Breastfed babies often have a bowel movement after every feeding for the first few weeks. If your baby is breastfeeding, he may go after every feeding or he may go several times a day. Don’t be alarmed by this. If it is runny and seedy that is perfectly normal for a breastfed baby. A lot of new moms mistake breastfed stools for diarrhea.

If your baby is a formula-fed baby, he will poop a lot in the beginning too. Formula-fed babies do not have as many bowel movements, generally, as breastfed babies but you can expect four or five poops a day in the first few weeks.

Babies that don’t poop for several days

Once your baby is about one month old, he may start having fewer bowel movements. If your baby is breastfed, he may go several days to a week without having a bowel movement. This is nothing to worry about. Exclusively breastfed babies rarely have problems with constipation. If he goes longer than a week, he seems to be in pain, or if you are concerned, call your pediatrician.

Formula-fed babies poops slow down at about a month as well. However, formula is more likely to cause constipation than breast milk. Most formula fed babies will have about one bowel movement a day. Stools should be soft. If you notice your baby’s stools are firm or hard and pellet-like, he may be constipated. If your baby goes longer than two or three days without a bowel movement and he is formula fed, you should give your pediatrician a call.

Babies that grunt and cry when they poop

If your baby does a lot of grunting when he poops don’t worry. This is normal. Babies sometimes grunt, cry or turn red when they have a bowel movement. This is nothing to worry about. A lot of new parents mistake this grunting for straining and constipation. Once your baby gets used to his bodily functions and how they feel, he won’t be as vocal about having them.

Green Poop

Every now and then the notorious green poop may show up in your baby’s diaper. You may take a look at it and ask yourself “how’d that get there?” There are many different causes for green poop. More than likely, if your baby has green poop, it’s nothing to worry about, but here are a few possibilities.


  • Iron-fortified formula - Some formula-fed babies will develop a case of green poop from the iron in the formula they are taking. As long as your baby is happy and not having any problems with constipation, there is nothing to worry about.
  • Jaundice - A baby that has jaundice may have dark or greenish colored stools. This normally goes away once baby is off of the bilirubin lights.
  • Dairy Sensitivity - Some breastfed babies are very sensitive to certain foods in their mom’s diet. If your baby is having problems with green mucousy stools, blood in his stools, spitting up a lot, or a skin rash, he may be sensitive to something in your diet. Dairy products are one of the most common causes of food allergies in babies. If you think this might be the problem, try eliminating milk and dairy products from your diet. It may take a couple weeks to see results from a dairy elimination diet. You should see improvement in a week or two. If you’re not sure, you can always try it out for a few weeks and then try having a cup of milk to see what happens. If the symptoms come back, then milk is probably the culprit and you will want to avoid it.
  • Foremilk/Hindmilk imbalance - If your baby is breastfeeding and has green frothy-looking poops, this may be a result of a foremilk/hindmilk imbalance. To put this simply, when a mom breastfeeds the first milk that comes out (foremilk) is thinner and lower in fat. After you have nursed for a bit, you will start to produce richer, fattier milk called hindmilk. Babies that receive too much of the thin foremilk and not enough of the richer hindmilk sometimes have problems with green stools and tummy aches. If you have been switching breasts a lot instead of letting baby get a good feed on one breast, you may have problems with this.
  • Other reasons - Sometimes babies just have greenish colored poop. The range of color in baby’s poops can vary. Any range of yellow, mustard to yellow/green is pretty normal for a baby. If baby is gaining well and happy then there is nothing to worry about.

Black poop

Black poop can be seen from iron supplementation. If your baby is taking an iron supplement or is on iron-fortified formula, he may have black or dark colored stools. Black stools, on the other hand, can also be of intestinal bleeding. If your baby has black tarry looking stools you should call your pediatrician.

Blood in baby’s poop

If you notice blood in your baby’s stool this may be alarming. Small streaks of blood in the stool are usually not something serious. However, if your baby has stools that look like dark red jelly or are streaked with mucous you should call your doctor right away. You should also call your doctor if your baby seems to be in pain or if your baby has persistent bleeding that does not go away.

Some other causes for blood in the stool are:

  • Small cuts or tears on the baby’s anus - Sometimes babies will develop an anal fissure (tear) from straining. You may notice small streaks of blood in baby’s stool
  • Diaper rash - If baby has had a diaper rash that has resulted in skin breakdown, he may end up with tiny amounts of blood in his diaper.
  • Food sensitivities- Dairy sensitivities may cause baby to have bloody/mucousy stools. (See above)