Background: Infantile colics are a common problem in the first months of life. During this period, a process of intestinal colonization rapidly occurs. A difference in the gut microflora could play an important role in the pathogenesis of colics, changing the metabolism of carbohydrates and fatty acids. Actually, in the literature, only few data have been collected about this topic. In this study, we evaluated intestinal microflora in breastfed colicky and non‐colicky infants. Methods: Seventy‐one breastfed infants, aged 3.2 ± 0.6 wk, free from episodes of gastroenteritis and without previous assumption of antibiotic and probiotic drugs, were enrolled in the study. They were divided into two groups: colicky (42 cases) and non‐colicky (29 cases), according to Wessel's criteria. Stool samples were collected, diluted and cultured on several selective media to detect lactobacilli, clostridia, Gram‐negative anaerobes and Enterobacteriaceae. Statistical analysis was performed using Student's t‐test, χ^2^ test and a non‐parametric test (Mann‐Whitney U‐test). Results: Differences in gut microflora were found among colicky and non‐colicky infants: colicky infants were less frequently colonized by Lactobacillus spp., and more frequently by anaerobic Gram‐negative bacteria.
Conclusion: Our study indicates that colicky infants have different patterns of gut microflora. Further studies are required to understand whether gut microflora is the primary cause of colics or its consequence.