For a long time, doctors and mothers alike have wondered what causes colic in young babies. Baby colic is defined as episodes of crying for more than three hours a day, for more than three days a week for three-week duration in an otherwise healthy child between the ages of two weeks and four months. The cause of colic is generally unknown. Fewer than 5 per cent of infants who cry excessively turn out to have an underlying disease.
Colic has previously been believed to be related to intestinal causes such as gas pains, psychological and social factors, and exposure to cigarette smoke.