Sample FAQ: Tummy cramps


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Normal babies have frequent, painful tummy cramps during and after feeding in the first few months of life. This happens when milk enters the stomach. The stretching of the stomach sends a signal to the large bowel, which squeezes its contents, causing crampy pain. Its medical name is the gastrocolic (stomach-large bowel) reflex. Mothers may hear the baby’s tummy gurgling and see the baby squirming, turning red, and even crying for a few minutes. If breastfeeding, the baby may let go of the breast. The baby usually settles after passing stool or gas. Everyone has the reflex, but it is more obvious in babies, who take in a lot of milk relative to their size and whose stool (poop) is more liquid. If the baby is hurting the mother’s nipple by tugging and clamping, she can take the baby off the breast until the baby settles a little, and resume breastfeeding once the baby gives hunger signs. If the baby lets go of the breast and cries, mothers can ease the pain by using the over-the-shoulder burping technique and applying pressure to the tummy for a few minutes. The cramps are often a sign of a good milk supply.

A) Describing the gastrocolic reflex

1) Normal behaviour

Tummy cramps, pain, and noise are one of the most common concerns of parents.

All normal, well-fed babies have painful bowel cramps, pass gas, or stool (poop) during or after feeds in the first few months after delivery. In short, they eat and then they poop. This is caused by the gastrocolic (stomach-large bowel) reflex.

The gastrocolic reflex shows that babies are taking in good amounts of milk. When the mother has an large milk supply, the baby tends to have more pain from the gastrocolic reflex. Babies who are underfed do not have as much bowel activity.

2) Misdiagnosing babies

The gastrocolic reflex is often misinterpreted as something else including:

  • Excess gas
  • The baby reacting to the mother’s diet
  • Gastroesophageal reflux or gastroesophageal reflux disease
  • Colic
  • Infant formula intolerance
  • Lactose intolerance
  • Teething

Each of these diagnoses can then result in worry for parents and ineffective and even dangerous interventions.

B) Reasons for the gastrocolic reflex

 The baby’s digestive system is one long tunnel and consists of the:

  1. Mouth
  2. Esophagus
  3. Stomach
  4. Small bowel
  5. Large bowel (colon)
  6. Rectum
  7. Anus

The gastrocolic reflex is the cramping (squeezing) of the baby’s large bowel in response to the baby taking in milk. When a baby breastfeeds:

  1. Milk enters the stomach through the esophagus.
  2. As the stomach is stretched, it sends a signal to the large bowel to move things along to make room for the milk that is coming from above.
  3. The stomach then allows small amounts of milk into the small bowel.
  4. The large bowel squeezes the contents, and these cramps can cause pain.

Everyone has the gastrocolic reflex but it is more pronounced in babies because:

  • Babies take in a lot of milk. They grow quickly and need a lot of milk relative to their size. In the first few weeks after birth, an average baby will take in about 150 millilitres per kilogram or 2 ½ U.S. fluid ounces per pound. For an adult weighing about 70 kg or 150 lbs, this would mean drinking about 10 litres or 3 U.S. gallons per day.
  • Babies have very liquid stools in the first few weeks. Their bowels are not mature and they can’t absorb all of the water in milk. This means the bowel has a lot of stool to move along.
  • Bacteria in the baby’s bowel make gas which must also be passed along the bowel.
  • Large amounts of liquid stool and gas must be squeezed over a long distance. Combined, the small and large bowels of a baby are about 3 metres (10 feet) long (Struijs 2009).

C) The baby’s behaviour during the gastrocolic reflex

When your baby has a painful gastrocolic reflex, you may notice:

  • The tummy gurgling as milk, stool, and gas move through the bowels.
  • The baby turning red, squirming, and crying for a few minutes.
  • If breastfeeding, the baby:
    • Tugging or clamping at the breast.
    • Letting go of the breast.
  • The behaviour starting suddenly, lasting a few minutes, and stopping quickly with the passing of stool or gas.

Tummy cramps may come on when the baby is sleeping and the baby can become quite noisy. The baby may:

  • Continue sleeping.
  • Cry a little while sleeping.
  • Wake up but return to sleep once the cramps resolve.
  • Wake up and:
    • Show hunger signs and need to breastfeed.
    • Need to be held and reassured before returning to sleep.
    • Need to be breastfed back to sleep.

D) Managing the gastrocolic reflex

If your baby is having pain from the gastrocolic reflex:

  • The baby may remain latched to the breast but will squirm a bit. Just let the issue resolve itself.
  • If the baby is hurting you by tugging and clamping, you may take the baby off the breast until the baby settles and gives you a hunger sign and then return the baby to the breast.
  • If the pain is bad enough that the baby lets go of the breast and starts crying, the baby can use some help to decrease the pain.

To ease the baby’s pain until the cramp, apply pressure to the tummy for a few minutes. We recommend using the over-the-shoulder burping technique. Stop once the baby is no longer in pain. 

Bicycling the baby’s legs is generally less helpful.

E) Duration of the gastrocolic reflex

As the baby ages:

  • The baby grows more slowly and relative to its size and weight, takes in less milk.
  • The bowel becomes better at removing water. This decreases the amount of stool a baby has to pass.
  • Stooling (pooping) frequency decreases. 

Pain from cramping is usually less severe by three months of age (Pados 2020).

F) Reflex and not reflux

Reflex and reflux are similar words but describe very different processes.

reflex is an automatic response to a stimulus. For example:

  • The dark part of the eye (pupil) will automatically shrink in bright light and grow larger in dark. 
  • The gastrocolic reflex, described above, happens when the bowel automatically contracts after the stomach stretches.

Reflux happens when a liquid in the body flows in the opposite direction than usual. Gastroesophageal (stomach-swallowing tube) reflux happens when the contents of the stomach rise into the swallowing tube and may cause the baby to spit


Pados BF, Basler A. Gastrointestinal Symptoms in Healthy, Full-Term Infants Under 7 Months of Age. J Pediatr Nurs. 2020 Jul-Aug;53:1-5

Struijs MC, Diamond IR, de Silva N, et al. Establishing norms for intestinal length in children. J Pediatr Surg. 2009 May;44(5):933-8

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