The term colic is used to describe any otherwise-healthy, well-fed baby that cries for more than three hours a day at least three times per week for more than three weeks, according to BabyCenter. Typically starting around 2 weeks of age in a full-term baby, colic typically goes away on its own around 3 or 4 months of age. In a premature baby, colic may begin later.
Instances of colic in babies are not affected by the gender of the baby, or by birth order or bottle feeding, according to BabyCenter. Having colic as a baby does not have any lasting effects on a child as they grow. Although there is no test to determine colic, a doctor typically examines a baby to determine if there is any other underlying medical cause that would account for the baby's crying before making a diagnosis of colic.
According to BabyCenter, the cause of colic is unknown, making treatment difficult. It is thought that it may be caused by a lactose intolerance in bottle-fed babies or by acid reflux, gas or general moodiness in other babies. Changes to the type of formula the baby is fed or the diet of a breast-feeding mother can help to alleviate colic in some cases.