What causes colic?

The exact cause of colic is unknown, but research indicates that colic may have multiple causes.

Potential causes

Some babies with colic may not adequately metabolise lactose in milk due to being born with insufficient levels of lactase enzyme.
  • The failure to break down lactose causes fermentation in the gut, which produces hydrogen and lactic acid4
  • The hydrogen can then bloat the colon, while lactic acid can result in an influx of water, which further swells the gut4
Some emotionally sensitive babies may have problems ‘turning off’ their crying response5
  • At four years of age, formerly colicky infants displayed more negative emotions, more negative moods during meals, and were more likely to report stomach-ache than those who had not experienced colic5
Women who smoke during pregnancy are twice as likely to have a colicky baby6
  • Smoking may trigger a rise in the hormone motilin, leading to indigestion and colic6
Food protein allergy
  • Food intolerances or both could contribute to colic in some children7.
Psychosocial factors
  • Such as parental anxiety or poor infant-family relationships may also contribute to colic8.
Maternal support
  • During and after pregnancy appears to reduce the rates of infant colic9. Specifically, high general social support during and after pregnancy were associated with a 45% and 49% reduction in reports of colic, while high levels of partner involvement with care was associated with a 40% reduction9.

What is the impact of colic?

One study of parents’ experiences reported that “colic overshadows everything”. Mothers and fathers felt powerless, were overwhelmed by strong feelings, and neglected other needs10.

The impact of colic on babies:
  • The baby will cry excessively2 but in general there is no long-term impact on the baby. The baby will continue to feed and gain weight normally
  • Colic may, in serious cases, lead to failure to thrive, dehydration and electrolyte imbalance4

crying for more than 20 minutes a day increases the risk of postpartum depressive symptoms four-fold

The impact on parents can be severe. Parents with a colicky baby are often distressed, stressed and tired and may fear that something is seriously wrong with their baby2. An inconsolable infant crying for more than 20 minutes a day increases the risk of postpartum depressive symptoms four-fold; infant colic doubles the risk11.

Colic is deeply distressing for both parents and baby, and can undermine parent-child bonding as well as increasing the likelihood of postnatal depression and non-accidental injury4.


"...crying for more than 20 minutes a day increases the risk of postpartum depressive symptoms four-fold..."