Although patients with irritable bowel syndrome (IBS) often report having family members with similar symptoms, few studies have investigated IBS in families. In the December 2003 issue of Gut, Jamshid S. Kalantar, MMedSc (Clin Epi), FRACP, and colleagues examined the frequency of IBS symptoms among family members of those with and without IBS. In this study, the frequency of IBS symptoms in 153 relatives of 74 patients with IBS was compared with 98 relatives of 62 IBS patient spouses. A valid self-report bowel disease questionnaire and the somatic symptom checklist were used to record gastrointestinal and somatic symptoms.
Results showed that IBS prevalence was 17% among the relatives of the patients with IBS, compared with 7% among the relatives of the patients? spouses (odds ratio 2.7 [adjusted for sex and age]; 95% confidence interval [CI], 1.2?6.3). The odds ratio was reduced to 2.5 (95% CI, 0.9?6.7) when adjusted for somatization score, as well as for age and sex. The authors concluded that, although their results support the hypothesis that IBS has either a genetic or an intrafamilial component, this aggregation can be explained, in part, by familial aggregation of somatization.