A baby who grunts, goes red in the face, and strains hard before passing a soft stool is usually doing something completely normal, not something wrong. In the first few months, babies haven't yet learned to relax their pelvic floor at the same time as they tighten their abdominal muscles — so they push hard against a closed system before anything moves. This is sometimes called "infant dyschezia," and on its own it is not a feeding or digestive problem.

Why straining happens, even with a normal, soft stool

  • The coordination is still developing — tightening the belly to push while relaxing the pelvic floor to let stool pass is a learned reflex, and very young babies haven't mastered it yet
  • Lying flat doesn't help — babies spend most of the day lying down, which works against gravity in a way adults, who are usually upright, don't experience
  • Exclusively breastfed babies can go several days between stools — breast milk is efficiently absorbed, so infrequent but normal, soft stools are common and not a sign of constipation by themselves
  • None of this means the stool is hard or that your baby is constipated — the key sign to watch is the consistency of what comes out, not how much effort it took to get there

Grunting or straining during a feed

  • Some babies grunt, strain or seem to "fight" the breast or bottle mid-feed — this is often immature digestion, swallowed air, or normal gas moving through, rather than a feeding problem
  • Occasional spit-up alongside this is common in young babies and is not usually a cause for concern on its own
  • If grunting during feeds is constant, your baby seems to be in real discomfort (not just effortful), or feeds are frequently interrupted by distress, mention it to your paediatrician rather than assuming it will pass

When it's genuinely normal — not a red flag

  • Soft, seedy, or paste-like stool (breastfed) or soft formed stool (formula-fed), however effortful the process looked
  • Normal weight gain and a baby who seems content between episodes
  • Grunting, straining or a red face that resolves once the stool passes

When to check in with your paediatrician

  • Hard, pellet-like, or dry stools rather than soft ones — this points toward true constipation, not just straining
  • No stool for many days along with a firm, distended, or painful-looking belly
  • Blood in the stool, or stool that looks black and tarry beyond the first days of life
  • Poor weight gain, persistent vomiting (especially forceful or projectile), or a baby who seems unusually lethargic or unwell
  • Fever, along with any digestive symptom

Effort is not the same as a problem — the stool itself, your baby's weight gain, and how they are between episodes tell you far more than how hard they strained to get there.

Frequently asked

Should I give my baby anything to help them pass stool more easily?

Don't start any remedy, massage technique, or product on your own — ask your paediatrician first, since what's appropriate depends on your baby's age, feeding type, and whether the stool itself is actually hard. Many babies need nothing at all.

Does this mean my milk supply or formula doesn't suit my baby?

Not usually. Straining with a normal, soft stool is about muscle coordination, not about what or how much your baby is being fed. If you're also seeing poor weight gain or other feeding difficulties, raise both together with your paediatrician.

At what age does this usually stop happening?

Most babies outgrow the straining and grunting pattern somewhere around 3 to 4 months, as the coordination between the abdominal muscles and pelvic floor matures — though the exact age varies from baby to baby.

Can tummy time or gentle leg movements help?

Some parents find gentle "bicycling" of the legs or supervised tummy time seems to help their baby pass gas or stool more comfortably. These are generally safe to try, but check with your paediatrician if you're unsure, especially for a very young or preterm baby.