Infantile or six-week colic is probably caused by spontaneous spasms of the small intestine, but no reason for these spasms has ever been proved. Some experts blame anxiety in the mother, particularly in a family without extended family support, for causing anxiety in the infant and subsequent gut spasms.
A baby with colic starts screaming for no apparent reason, draws the legs up and looks pale. After a few minutes, the attack subsides and the infant appears normal, then after a short interval the screaming starts again. This pattern repeats itself several times a day. No tests can be performed to confirm the diagnosis.
Changes in diet and formula, different foods for the mother of breastfed infants, alterations to feeding times and positions, increases or decreases in the degree of attention paid to the child and antispasmodic drugs or paracetamol can all be tried, with varying degrees of success.
The problem always goes away in due course, usually at 12 to 16 weeks of age.