April 1st 2003ABSTRACT: Infant colic is a diagnosis of exclusion; its true cause is not known. To rule out alternative diagnoses, obtain a detailed history, look for clues to an underlying organic disease or genetic syndrome, and perform regular head-to-toe physical examinations. The interventions most commonly used to treat colic include modification of parental behavior (such as increased carrying of the infant or decreased infant stimulation), milk- and/or soy-free formulas, modifications in the diet of a breast-feeding mother, soothing measures (such as car rides, rocking, or use of a pacifier), anticholinergic agents, sedatives, and alternative medicine approaches (such as sucrose solution, herbal teas, or infant massage). The medications used to treat colic-such as antispasmodics and anticholinergics-can have serious adverse effects; discuss the pros and cons of drug therapy with parents before prescribing these agents. Remind parents that colic resolves by age 3 to 4 months, regardless of the intervention used.