This article defines "colic" as excessive crying in young infants and suggests some specific diagnostic criteria. The three main theories of single causes are reviewed: feedings, psychosocial environment, and problems in the infant. In place of these oversimplified explanations, this article proposes an interactional model that considers both intrinsic and extrinsic factors. Recommendations for management include suggestions for handling the infant, the environment, and their interaction. Some suggestions are then offered for improving the quality of future research.