In most cases colic usually develops in the second or third week of baby's life and worsens after one month when baby is six weeks old. At around twelve weeks of life it starts to improve with some babies settling quickly and others improving slowly.

The colic can start at a later period, but most babies are free of colic by the time they reach six months of age. Thus colic usually lasts for a period of three months. Premature babies tend to start and finish their colic later than term babies.