RESUMEN
BACKGROUND: The aetiology of irritable bowel syndrome (IBS) is multifactorial, including genetic and environmental factors. Previous studies have suggested that low birth weight and family environment during childhood are associated with developing IBS. METHODS: A survey was sent to all individuals in a UK twin registry. Questions included IBS diagnosed by the Rome IV criteria and if a doctor had previously diagnosed them with IBS. Subjects were categorized as having IBS by Rome IV criteria, a medical diagnosis of IBS or no IBS. Further questions included subjects' recollections of their parents' responses to illness in both the respondent as a child and in the parents themselves. Information regarding birth weight and gestational age have been collected previously. KEY RESULTS: 4258 subjects responded to the questionnaire (51.7%), mean age of 52 (SD 14) years, of whom 98.5% were white and 89.6% female. The mean birth weight was 2.4 (0.6) kg. 5.1% satisfied the Rome IV IBS criteria, the same prevalence as the UK population. However, 14.1% had a previous medical diagnosis of IBS. There was no association found between birth weight and IBS or a medical diagnosis of IBS. On multivariable regression analysis, including parental responses to illness, subjects recalling a parent responding to the parent's bowel symptoms by excusing themselves from household chores were associated with a Rome IV diagnosis of IBS (OR 2.19 (95% CI 1.17-4.10), P = .013). CONCLUSIONS AND INFERENCES: There was no association between birth weight and IBS. However, observing their parents excuse themselves from household chores when they had bowel symptoms was associated with IBS in later life.