Background

Definition Infantile colic is defined as excessive crying in an otherwise healthy baby. The crying typically starts in the first few weeks of life and ends by age 4-5 months. Excessive crying is defined as crying that lasts at least three hours a day, for three days a week, for at least three weeks.1

Incidence/prevalence Infantile colic causes one in six families to consult a health professional. One population based study (409 breastfed or formula fed infants) found the incidence of infantile colic to be 3.3-17%, depending on the definition used and whether the symptoms were reported prospectively or retrospectively. The incidence was 9% using the definition given above.2 One randomised controlled trial (RCT) (89 breast and formula fed infants) found that, at 2 weeks of age, the incidence of crying more than three hours a day was 43% in formula fed infants and 16% in breastfed infants. The incidence at 6 weeks was 12% and 31% respectively.3

Aetiology The cause of infantile colic is unclear. It may be part of the normal distribution of crying. Other possible explanations are painful gut contractions, lactose intolerance, gas, or parental misinterpretation of normal crying.1 One large survey found that the social factors that influenced reporting of infantile colic included the age at which the woman had her first child, the time she had spent in full time education, and her occupation. Older women who had spent the longest in full time education and in non-manual occupations were the most likely to report infantile colic.4 …