A review of colic research supports the theory that colic may be caused by pain, particularly pain generated by gastrointestinal causes. At the same time, it also supports the view that disturbing crying in the first 3 months of life may be secondary to behavioral-interactive problems or simple parental misinterpretation of cry. In fact, a closer look at the methodology of colic studies along with our preliminary results suggest there may be at least two different patterns of disturbing infant crying. It is possible that one is associated with true pain and the other not. Dependence on retrospective parental reports alone to substantiate the presence of pain is only as reliable as parent interpretation of crying. Although specific cry patterns may represent specific infant conditions, parents may not be accurate interpreters of those patterns. In trying to determine the presence of gastrointestinal pain in colicky crying, close attention therefore should be given to the nature of the cry. Specific attention to qualitative and quantitative aspects of crying in colicky infants is identified as important by our pilot work. In the future this may help to explain the apparent discrepancies in the colic literature and to determine to what extent infant colic is a true pain syndrome.