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Newborn Grunting: Grunting Baby Syndrome

Medically Reviewed by Dr. Po-Chang Hsu, MD, MS
What is grunting baby syndrome, and why does it happen?

Does your baby grunt especially loudly during bowel movements? Do they sometimes cry when trying to pass stool?

Although you might be tempted to pass these off as symptoms of constipation, if you answered yes, there’s a chance your baby could be suffering from grunting baby syndrome (GBS).

While this condition might sound silly, it can actually bring quite a bit of discomfort and pain to your little one.

Let’s talk about GBS, what causes it, and more importantly, how you can bring your baby some relief.

Key Takeaways

  • Grunting Baby Syndrome (GBS) is when babies grunt and strain due to difficulty coordinating stomach and pelvic muscles for bowel movements.
  • GBS symptoms include crying, straining, turning red, and squeezing abdominal muscles during bowel movements.
  • GBS usually resolves on its own by the time a baby is 3-4 months old, and a hands-off approach is recommended.
  • If grunting is not followed by a bowel movement or occurs with every breath, consult a doctor as it may be caused by other conditions like constipation, acid reflux, or respiratory distress.

What Is Grunting Baby Syndrome?

At first glance, grunting baby syndrome might look like constipation, but if the stool inside your baby’s diaper is soft, chances are those noises they’re making are being caused by something else (1).

With GBS, the grunting isn’t caused by hard stool. It’s caused by the baby’s body not recognizing the signals it needs to go to the bathroom.

We’ll explain. Have you ever tried to rub your stomach while patting your head simultaneously? It takes a level of coordination that we’re not born with. Believe it or not, this kind of coordination is also required to have a bowel movement.

To pass stool, our stomach muscles have to flex, and at the same time, our bodies tell our pelvic muscles to relax. Grunting helps babies flex their stomach muscles, so they often do this to help pass waste (2).

Unfortunately, while the grunting helps your abdominal muscles flex, it doesn’t help the pelvic muscles relax. So your baby has to grunt and push the stool down repeatedly until their pelvic muscles get the memo to relax and let the stool pass.

This can cause pain and discomfort until your baby learns to coordinate these two muscle groups.

What Does Grunting Baby Syndrome Look Like?

Perhaps you’re beginning to suspect your baby is suffering from GBS, but you want to be sure.

If your baby is experiencing GBS, they will likely also do the following things when trying to have a bowel movement:

  • Crying or screaming.
  • Straining.
  • Turning red or even dark purple.
  • Squeezing their abdominal muscles.

They will experience several, or all, of these symptoms for five to ten minutes before finally passing stool and feeling comfortable once more.

How Can I Help My Baby With GBS?

The bad news is there’s nothing you can do to stop or cure grunting baby syndrome in your baby. The good news? It will clear up on its own by the time your baby is 3-4 months old. So when it comes to GBS, there really isn’t much to worry about.

Some doctors might tell you to ease your baby’s discomfort by stimulating their anus with cotton balls and Vaseline or an anal thermometer, but this may hurt more than it helps.

If you continuously use stimulants to help your baby pass stools, it may take them longer to learn how to relax their pelvic muscles on their own.

Sometimes Doing Nothing Is Best

Your baby needs to learn to coordinate these muscle groups without the help of stimulants, which is why a hands-off approach is the best way to go with GBS.

When It’s Not GBS

Not all baby grunting is caused by grunting baby syndrome. Grunting can be a symptom of several different conditions.

If your baby’s grunting episodes are not followed quickly by a bowel movement, or if your baby is grunting with every breath, then GBS is likely not the cause. One of the following conditions might be the reason.

1. Constipation

While constipation isn’t the underlying cause of GBS, it can cause your baby to grunt. But don’t worry; it’s fairly easy to tell the difference between constipation and GBS.

When suffering from constipation, your baby may:

  • Grunt but not have a bowel movement right after the grunting episode.
  • Go three to four days between bowel movements.
  • Have hard, compact stools when they have a bowel movement.

Luckily constipation is usually fairly easy to fix. It could be caused by dehydration. Or, if your baby is formula-fed, an ingredient in the formula may be the cause (3).

If you think your baby is experiencing constipation, contact your doctor. They can tell you if there’s something at home to try and ensure it’s not caused by a more serious disorder such as hypothyroidism or Hirschsprung’s disease.

Although both of these conditions are rare, it’s better to be safe when it comes to your little one.

2. Acid Reflux

Sometimes babies will also grunt when they suffer from gastroesophageal reflux (GER). GER is caused when your baby’s lower esophageal sphincter is underdeveloped and allows milk and stomach acid to leak back into your baby’s throat (4).

GER can cause your baby to experience symptoms such as colic, crying, vomiting, and yes, even grunting.

Luckily, acid reflux is easy to diagnose and treat. Your doctor might tell you to adjust your baby’s position during and after feedings or, if you’re nursing, to avoid foods that could worsen the acid reflux. These may include spicy foods and carbonated beverages (5).

In more severe cases, your doctor can also prescribe antacids or special formulas to help your little one.

In most cases, acid reflux in infants resolves on its own, but in some extreme cases, surgery may be required to prevent the stomach acid from moving up.

3. Respiratory Distress

Is your baby seemingly grunting with every breath they take? This could be a sign of a serious respiratory issue (6). Grunting with every breath could be a sign of pneumonia, asthma, meningitis, or even heart problems.

If the grunting is accompanied by any of the following symptoms, it’s important to contact your doctor:

  • Weight loss.
  • Lethargy.
  • Fever.
  • Blueish tint on your baby’s tongue.
  • Longer pauses between breaths.
  • Nasal flaring.
  • Belly breathing or drawing in the chest when breathing.

While these issues can be helped in most cases, they can also cause long-term damage if left untreated. We can’t say it enough — if your child is experiencing any combination of these symptoms, it’s important to contact your doctor immediately.

4. Other Causes of Baby Grunting

Here are some other causes of grunting in babies. They are rare but can be lethal when they happen, with or without signs of respiratory distress. It is vital that parents can recognize them and seek proper medical attention when they happen. We provide a list of some of them here, along with their associated symptoms besides grunting and respiratory difficulties:

  • Sepsis (blood poisoning usually due to infection): Fever, fussiness, confusion, floppiness, decreased urination, and jaundice (skin color turning yellow).
  • Meningitis (infection of the membrane layer protecting brain and brain stem): Fever, stiff neck, vomiting, floppiness, rash, refusal to eat, swelling of the fontanelle (the soft spot on baby’s head), cold hands and feet, fatigue, and seizure.
  • Heart Failure: Trouble gaining weight, too tired to eat, fatigue, sleeping too much, swelling of body parts, skin turning blue, and sweating after feeding or play.

Grunting Baby Syndrome FAQs

How Long Does Grunting Last in Newborns?

Typically, grunting baby syndrome occurs during the first few weeks and generally subsides by 3-4 months.

Why Is Baby Grunting Worse at Night?

Newborns have immature digestive systems, and lying flat can exacerbate gas and bowel movement grunts.

Does Grunting Mean Autism?

No, grunting in newborns is normal and not a sign of autism.

When Should I Worry About Baby Grunting?

If grunting is accompanied by blue or pale skin, labored breathing, or refusal to feed, seek medical attention.

The Bottom Line

It’s not fun to hear that what you once thought was just a cute sound could be grunting baby syndrome. The good news is many issues that involve grunting are easy to fix or will fix themselves.

(Who would have thought your baby’s body would have to learn to poop correctly?)

It’s important to remember that you are your child’s advocate. If you feel there’s something more going on, whether it be constipation, acid reflux, infections, heart failure, or a severe respiratory issue, contact your doctor and get your baby looked at. Trust your gut!

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Headshot of Dr. Po-Chang Hsu, MD, MS

Medically Reviewed by

Dr. Po-Chang Hsu, MD, MS

Po-Chang Hsu, MD received his medical degree from Tufts University in Boston, Massachusetts. Dr. Hsu has interests in both pediatrics and neonatology, and he also loves writing, walking, and learning new languages.