RESUMO
OBJECTIVE: To determine a family aggregation pattern of Irritable Bowel Syndrome (IBS). DESIGN: it is a case-control study with a 1.2 ratio. SETTING: External consultation of a general family medicine practice. PARTICIPANTS: men and women from 18 to 60 years old. Cases (40): people with IBS according to the Rome IV criteria, and Controls (80): relatives without gastrointestinal disease. MAIN MEASUREMENTS: Sociodemographic variables, related stressful events, predominant evacuation patterns, and family repetition patterns for IBS. Data were analyzed with descriptive and inferential statistics. Chi-square for categorical data (< p.05 as significant) estimate of ORs with 95% confidence interval. The institutional ethics committee approved it. RESULTS: The IBS presentation pattern was repeated in relatives, mainly first-degree. The risk of suffering from IBS was higher when the father reported it (OR 11.2 (95% CI; 1.2 -100.1), than the mother OR 3,7 (95% CI; 1.4 - 9.9), sibling OR 2.8 (95% CI; 1.1 - 6.6. In both groups, the relative who most frequently presented IBS was in the collateral line (sibling) (37.5% in cases vs. 17.5% in controls (p=0.023). In both groups, the predominant gender was female, with 80. 0% in cases and 57.5% in controls. CONCLUSION: SII has a familial recurrence pattern in the Mexican population. The disease is more frequent in first-degree relatives. It is important to elucidate the importance of the role that plays genetic background vs. the influence of the family environment in SII.