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    What Does Mucus in Baby Stool Mean?

    Updated 29 November 2021 |
    Published 14 August 2019
    Fact Checked
    Medically reviewed by Dr. Anna Targonskaya, Obstetrician and gynecologist
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    If you see mucus in your baby’s diaper, you may feel concerned. While mucus can sometimes be a totally normal occurrence, it can also be a sign that a baby needs medical attention. Read on to learn when you should be concerned about mucus in baby stool.

    What causes mucus in baby stool?

    There are many possible causes of mucus in baby stool. It may just mean that your baby has been drooling more than normal. However, mucus in poop can also be a warning sign of a medical problem, like an allergy or infection.

    The intestines make mucus to help stool pass through smoothly. Sometimes, this mucus can end up in your baby’s diaper. When your baby’s poop contains mucus, you’ll probably notice that the inside of their diaper looks slimy. The poop tends to be a greenish color, with shiny strings streaking through it. The mucus may look jelly-like, rather than string-like.  

    If your baby has been drooling a lot recently, the mucus may just be from undigested saliva. Babies can drool frequently when they’re teething. Excessive saliva in digestive tract and teething pain may irritate the intestines, which increases the amount of mucus in baby’s stool. Babies who have infections, like strep throat or tonsillitis, can also drool more than normal until they start feeling better.

    Some babies are allergic to cow’s milk proteins. This type of allergy is known as allergic colitis, — around 2 to 3 percent of babies have it. Usually, symptoms appear within the first two months of a baby’s life, though they can appear later. Symptoms can include blood or mucus in the stool. Babies with allergic colitis can also vomit or have diarrhea. If your baby has this milk allergy, you may also notice that they’re very fussy.

    Mucus in baby poop can also be caused by an infection, like a stomach flu. These infections irritate a baby’s intestines, so they can lead to inflammation and mucus. If your baby has an infection, they may have other symptoms in addition to the mucus in their poop. They could have a fever, or they could be irritable.

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    Mucus in newborn stool

    Newborn babies produce meconium, a special type of poop, in their first days of life. It’s black and sticky, and parents compare it to motor oil or tar. Meconium is made from various substances that babies ingest while they’re in utero, including amniotic fluid, skin cells, and mucus. This black poop will lighten up if your baby is feeding well, and in a few days, their poop will be a normal dark green or yellow color.

    Is baby poop with mucus dangerous?

    Baby poop that contains mucus often isn’t dangerous. However, mucus is sometimes a sign that your baby has a health issue that needs to be addressed. If your baby is experiencing other symptoms, or if the mucus keeps appearing in their diaper, they may need medical attention.

    While mucus can just be a sign that your baby has been drooling, you shouldn't ignore it. Baby poop with mucus can be a warning sign of a more serious medical concern, like an allergy or infection. This can be the case for babies who have other gastrointestinal symptoms, such as vomiting or diarrhea. A fever that accompanies mucus in stool can also be a cause for concern. If your baby has mucus in their stool and seems unwell, take them to their pediatrician to get checked out. If your baby seems fine other than the mucus in their stool, keep an eye on them. They should be seen by a doctor if the mucus keeps showing up for two days or more.

    In rare cases, baby poop with mucus can be a sign of intussusception, a medical emergency. This means the baby’s intestines have slid into each other, blocking blood flow to the intestines. Babies with this condition often have stools that look like dark red jelly. Call your child’s doctor right away if you notice this kind of stool.

    Mucus diarrhea in babies: what's the reason?

    Mucus diarrhea in babies can be alarming for parents. If your baby has loose or runny stools that contain mucus, you may wonder what’s wrong. While there are many possible causes, diarrhea is usually caused by a virus. Allergies can also be responsible.

    Since baby poop is normally fairly runny, it can be hard to tell if your baby has diarrhea. As a rule of thumb, if they suddenly have runnier or more frequently stools, and this lasts for three or more stools, they have diarrhea. The presence of mucus is another clue that your baby has diarrhea.

    Acute diarrhea is usually caused by a viral infection in the intestines. Many viruses, including rotavirus, can be responsible for this type of diarrhea. The bacteria that cause foodborne illnesses, like salmonella, are another possible culprit. The main concern with diarrhea is the risk of dehydration. When babies get dehydrated, their soft spot can become sunken or depressed.

    Mucus diarrhea in babies may also be a sign of allergic colitis, an allergy to milk proteins. This type of diarrhea can be easily treated; mothers who are breastfeeding will just need to eat a dairy-free diet, and mothers who use formula will need to switch to a hypoallergenic formula. It takes time for a baby’s intestines to heal, so their stools may take a few weeks to get back to normal.

    There are many possible causes of mucus in baby poop. If you’re worried that your baby’s mucus is caused by a medical condition, take them to their pediatrician right away. Their doctor can determine the source of the mucus and, if necessary, begin a treatment.

    History of updates

    Current version (29 November 2021)

    Medically reviewed by Dr. Anna Targonskaya, Obstetrician and gynecologist

    Published (14 August 2019)

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