Back groundThe precise etiology of infantile colic has not been elucidated after many years of research. In this study, we aimed to determine the association of fecal calprotectin with infantile colic.MethodThis case control study was performed on colicky infants referred to pediatrics clinics in Zanjan over a 6-month period. Infantile colic was clinically defined based on wessel criteria. The control group consisted of healthy infants matched for age, sex, weight, and type of feeding with the case group. Fecal calprotectin levels were measured in both groups by the ELISA method.ResultsForty infants were divided equally into case and control groups. The cases consisted of 11 boys (55%) and 9 girls (45%) with a mean age of 63 days and in the control group there was 12 boys (60%) and 8 girls (40%) with mean age of 48 days. Fecal calprotectin was positive in 17 (85%) cases and 6 (30%) controls. This difference was statistically significant. There was no significant difference in fecal calprotectin regarding sex, age, weight and type of nutrition in both colicky infants and controlsConclusionFecal calprotectin levels in colicky infants were significantly higher than healthy infants.