Colic is crying in a baby that lasts for longer than three hours a day and is not caused by a medical problem. It occurs in almost all babies to varying degrees. Infantile colic typically begins at about two to three weeks of age, reaches its peak at two months, begins to subside by three months, and is gone by three and half to four months of age.
But the frustrating fact remains that there is no one proven cause of colic. It is generally believed that if one or both parents were colicky, their baby is more at risk. The crying begins suddenly, often after feeding, in the late afternoon or early evening, just when parents are most exhausted. The babies hands may be in a fist, the legs may curl up, and the belly may seem swollen. It often winds down when the baby is exhausted, or when gas or stool is passed.