Color of the Day: Solving Bowel Movement Mysteries

Color of the Day: Solving Bowel Movement Mysteries

  • Posted by Dr. Jay Gordon

Stools in breastfeeding babies are predictably green, brown, yellow or orange. There is a wide variety of color and consistency of bowel movements.  In my glamorous job as a pediatrician, I discuss this hot topic every day.

We shouldn’t be any more surprised to see a variety of bowel movements in our babies than we would in anyone of any other age.  In breastfed babies, the mom’s diet can affect the color or consistency of a baby’s stools, particularly if the baby is showing an allergic reaction to a certain food or food group.

Greenish or Yellow/Brown, grainy or seedy
This is the transition between meconium and a regular breastfed stool and begins as mom’s milk is coming in on the second, third or fourth day of life.  There may be three stools each day, ten, or even twenty.  Occasionally, even a baby in the first week of life will skip a day and have no bowel movements at all.  Call your doctor to discuss this even though it is normal.  This does not require a dietary change or supplementation of a breastfed baby.


Frequent Watery Stool often “Greener” than usual
How can you spot diarrhea in a baby who has loose frequent stools every day?  This type of poop is “diarrhea” in a breastfed baby.  It can be due to a virus, a bowel infection, stress, anxiety or a food intolerance.

Black stools often accompanied by constipation
This is the result of iron supplementation. Iron fortified infant foods and infant vitamins can cause constipation. A healthy breastfed baby does not need iron supplementation. The iron in breastmilk is much more bioavailable than any other form.

Green, frothy stools
This can be a result of a hindmilk/foremilk imbalance. A true imbalance is rare. It is often seen accompanying a forceful letdown. Lactation consultants will help moms find a nursing pattern which works to combat this problem.  If letdown it too forceful in the early weeks, the solution can be to allow milk to leak into a cloth diaper during letdown, then latch baby back on.  Feeding two to three times off the same side may also show improvement. Caution should be used with same side feeding as it can decrease supply.

Another cause of malabsorption in the intestines can be teething. The profuse saliva of a teething baby can cause irritation in the intestines interfering with proper absorption.  When babies teethe, we can see lots of drooling.  Large quantities of saliva is swallowed which can irritate the intestines causing runny, acidic stools. This can also cause a rash in the diaper area.

In summary, stools in breastfeeding babies are predictably green, brown, yellow or orange.  It is runny and has curds almost every time.  It changes color with viruses, may have a small amount of blood (call your doc) and may come once a day and even taper off to once a week or more after a few weeks of age.  Formula feeding babies may show a little trickier set of changes involving constipation and diarrhea.  This is just one small reason to strongly recommend and support breastfeeding your baby.


  1. ritu

    hi my son is 12 months old usually he have wind problem but today when he poo it is of usual mustard coloured first half is really hard but last is like greasy loose is it normal or sign of diarrhea he is introduced to solids few days ago?

    1. Cheryl Taylor

      Take a good look at what solids you are beginning with. Fresh, ripe fruit and steamed vegetables are the best place to start. Any protein other than breastmilk, particularly any meat or egg, can cause a very foul smelling bowel movement and cause a considerable amount of gas while baby's body is trying to break it down.

  2. Megan S

    My almost 8 week old son has had a bowel movement that is very dark brown, almost black in colour and VERY watery and frothy. He is on an iron supplement could this be causing the consistancy to change and colour. I always thought iron would make you constipated not the other way around. Should I be concerned and see his Doctor?

    1. Cheryl Taylor

      Iron supplement's can cause the bowel movement to be black in color and/or harder in consistency than normal. If your baby is breastfed there is no reason to be giving iron supplements. The iron that is in breastmilk is by far the most bioavailable iron there is.

      1. Megan S

        He is taking in breastmilk and being supplemented by a hypoallergenic formula as well. He had his blood taken to check his iron and it was low thats why he is on the iron supplement. He was having and and just started to again have blood streaked mucous in his bowel movements so I am assuming his iron was low due to that, but not sure.

        1. Cheryl Taylor

          What were the levels in his bloodwork? Often medical professionals say that an infant has "low" iron if they are at the bottom of what is "average" when the baby actually doesn't have low iron at all. Be sure you know exactly what the level. Take as an example a 2 month old. Normal levels range from 10 to 18 for hemoglobin. If a baby has a level of 10 that doesn't make them low in iron. They are merely on the lower side of normal. It is not something that needs to be higher to be "good" when it's in normal range.

          Had he been sick within the month prior to the levels being checked? When an infant is sick it is a normal biological process for iron levels to lower, because iron can feed bacteria and the body naturally helps in the process of recovery by lowering those levels and then raising them after the illness has past. This process can take up to a month.

          There are a lot of things to think about when you bloodwork!

  3. Valentina 3 week year old baby is exclusively breastfed and Her BM always regular yellow/ seedy and now for all most a week is green/mucous i don't drink milk products but i had milk basis cookies for the past week can it be the case of this?

  4. Stephanie


    My daughter is 3 months old and is breastfed only. This past weekend her stool was not mustard/seedy like usual but more a deep orange to brown with pudding texture. And it smelled awful. I did notice in one of the bm's that there was a speck of blood. Could this all be related to dairy in my diet??


    1. Cheryl Taylor

      Possible. There's always the possibility of influence from what is in mother's diet. I usually tell moms to keep an eye on it for a week and see if it continues, because a virus in a breastfed baby may be seen only in a change in BM that resolves within 7 days.

  5. Ann

    My son just turned 8 weeks today. I've noticed since the beginning of 7 weeks that his poops in addition to being less frequent (I realize that's normal) is often times much thicker and a dark yellow almost a brownish yellow. Is that normal? He is exclusively breastfed and the only change we've experienced is I'm currently dealing with oversupply issues.


    1. Cheryl Taylor

      With an exclusively breastfed baby you may see variations in consistency or color, but it is still perfectly normal. Any range of yellow to brown is still normal. Oversupply can change the balance of hindmilk and foremilk, but there isn't need for concern unless the BM is green consistently.

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