Newborn grunting and straining: what is normal and what to watch
It can be startling the first time you see your newborn go bright red, grunt with effort, and look as though they are trying to lift a small car. A minute or two later they produce a soft, perfectly normal nappy and seem entirely unbothered. If this sounds familiar, you are almost certainly watching something completely normal. This guide explains why newborns grunt and strain, what infant dyschezia is, and the small number of signs that genuinely warrant a call to your GP.
Why newborns grunt in the first place
Your newborn arrived with a digestive system that works, but a nervous system that is still very much a work in progress. The muscles involved in digestion, passing gas, and having a bowel movement are all there, but the coordination between them has not been fully figured out yet. Grunting is simply the sound of effort as your baby uses their abdominal muscles in ways that are brand new.
Think of it less as a problem and more as practice. Every grunt, every push, every strain is your baby's nervous system learning the ropes. This is why grunting and straining is so common in the newborn period and so rare by the time babies are 4 or 5 months old. Their system has had a chance to mature.
Grunting during sleep: active sleep is noisy
Many parents notice their newborn making all sorts of sounds during sleep: grunts, squeaks, little cries, and even occasional whimpers. This is entirely normal and is related to the sleep cycle. Newborns spend a large proportion of their sleep time in active (REM) sleep, the lighter stage where the brain is very active and movements and sounds are common.
Grunting during sleep is not a sign of discomfort or distress. Your baby is simply in active sleep, processing the day's input. If you watch carefully you will notice they are still breathing steadily and not waking up. The exception, as always, is a grunt that accompanies every single breath, which has a different quality and rhythm. That needs immediate medical attention (see below).
Infant dyschezia: a name for normal straining
Infant dyschezia is the clinical term for a pattern that many parents find alarming: a young baby who strains, pushes, goes red in the face, grunts, and may cry for 10 to 20 minutes before finally passing a completely soft, normal stool. It typically appears in the first weeks of life and resolves on its own by 3 to 4 months.
The cause is a coordination mismatch. To have a bowel movement, you need to do two things at the same time: push with your abdominal muscles and relax your pelvic floor. Adults do this automatically. Newborns have not learned this coordination yet. So your baby pushes with their abdomen but tightens their pelvic floor at the same time, which means nothing can get out. They strain harder. They cry. They go red. Eventually the coordination clicks, the pelvic floor relaxes, and out comes a soft, normal poo.
Infant dyschezia is diagnosed based on age (under 9 months), the pattern (straining and distress for at least 10 minutes), and crucially, the outcome: a soft or liquid stool. The AAP includes it in the Rome IV criteria for functional gastrointestinal disorders of infancy.
Dyschezia is not constipation
This distinction matters, because the two look similar at first glance but have different causes and very different responses. Constipation means the stool itself is hard, dry, and pellet-like. A baby with true constipation produces firm, rabbit-pellet stools and may go several days between movements.
A baby with dyschezia produces soft or even runny stools after significant effort. The stool is normal. It is only the getting-it-out process that is effortful. If your baby's stools are soft, they are not constipated, regardless of how long or hard they had to work to produce them.
Why intervening with dyschezia makes it worse
It is tempting to help. When you see your baby struggling, reaching for a glycerin suppository or using rectal stimulation to help them along feels kind. For dyschezia, it is actually counterproductive. The whole point of the straining process is that your baby's nervous system is learning to coordinate those two muscle groups. Every time you bypass that process with external stimulation, you interrupt the learning.
Babies who have rectal stimulation used regularly for dyschezia can become dependent on it and take longer to develop the coordination on their own. Unless your GP or health visitor has specifically assessed your baby and recommended it, the most helpful thing you can do is give your baby the time and space to work through it.
When grunting or straining is a concern
Most grunting and straining is entirely benign, but a few signs warrant prompt attention:
Grunting with every breath (grunting respirations). This is a completely different sound from the straining grunt. Respiratory grunting is a consistent, repetitive sound that occurs with each and every exhale. It is a sign that your baby is working hard to breathe and is a medical emergency. Call 999 immediately if you notice this alongside rapid breathing, flared nostrils, the skin pulling in at the neck or between the ribs, or bluish colouring around the lips.
Hard, dry, pellet-like stools. This is true constipation and is worth mentioning to your GP or health visitor, particularly in a breastfed newborn (breastfed babies very rarely become constipated, so it is worth investigating). Your GP may recommend a small amount of cooled boiled water or, if needed, an infant-appropriate laxative.
Blood in the stool. Small streaks of blood on the outside of a hard stool can result from a small anal tear and are usually not serious, but always worth showing to your GP. Larger amounts of blood, or blood mixed through the stool, need same-day assessment.
A distended, hard abdomen. If your baby's tummy looks or feels unusually bloated and firm between feeds, speak with your GP.
When to expect it to settle
General newborn grunting settles as the weeks go by and your baby's nervous system matures. Infant dyschezia specifically tends to resolve by 3 to 4 months. If your baby is still having significant straining difficulties past 4 months, or if you are ever worried, your GP or health visitor is always the right person to speak to. You know your baby best.
Frequently asked questions
Why does my newborn grunt so much?
Newborns grunt because their nervous system is still learning to coordinate the muscles involved in digestion, passing gas, and having a bowel movement. The grunt is simply the effort of using abdominal muscles that are very new. It is a normal developmental feature of the newborn period and settles as your baby's system matures.
Is grunting normal in newborns?
Yes, grunting is very common and usually completely normal. Most newborns grunt regularly during feeds, while passing gas, during sleep, and when having a bowel movement. The exception is grunting with every breath, which is a different sound and a sign of respiratory distress that needs immediate medical attention.
Why does my baby strain and go red when pooing?
This is most likely infant dyschezia. It happens because your baby has not yet learned how to coordinate relaxing the pelvic floor at the same time as pushing with the abdomen. They grunt, strain, and go red, then produce a soft, normal stool. It resolves on its own by 3 to 4 months as the nervous system matures.
Is infant dyschezia the same as constipation?
No. Infant dyschezia involves straining and distress before passing a soft, normal stool. Constipation means the stool itself is hard, dry, and pellet-like. If your baby strains a lot but then passes a soft or runny stool, the stools are not constipated regardless of how much effort it took.
Should I use a suppository or glycerin stick to help my baby poo?
For infant dyschezia, no. Intervening with suppositories or rectal stimulation interrupts the learning process your baby's nervous system is going through. It can actually make dyschezia last longer. Unless your GP or health visitor has specifically recommended it, the best approach is to let your baby work through it themselves.
When does grunting while pooing get better?
Infant dyschezia typically resolves by 3 to 4 months of age as the nervous system matures and coordination improves. General newborn grunting also settles during the early months. If symptoms persist past 4 months or you are concerned, speak with your GP or health visitor.
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