Familial association in adults with functional gastrointestinal disorders

Objective: To evaluate the association between functional gastrointestinal (GI) symptoms and a family history of abdominal pain or bowel problems. Subjects and Methods: A valid self-report questionnaire that records GI symptoms and spouse's and first-degree relatives' history of abdominal pain or bowel troubles and includes the psychosomatic symptom checklist (a measure of somatization) was mailed to an age- and sex-stratified random sample of Olmsted County, Minnesota, residents aged 30 to 64 years. A logistic regression model that adjusted for age, sex, and somatic symptom score was used to estimate the odds ratio (OR) and 95% confidence interval (CI) of a positive family history for each functional GI disorder. Results: Six hundred forty-three (72%) of 892 eligible subjects returned the survey. Reporting a first-degree relative with abdominal pain or bowel problems was significantly associated with reporting of irritable bowel syndrome (OR, 2.3; 95% CI, 1.3-3.9) and dyspepsia (OR, 1.8; 95% CI, 1.05-3.0) but not constipation, diarrhea, or gastroesophageal reflux. The reporting of a spouse with abdominal pain or bowel problems was not associated with any of these disorders. Conclusions: A history of abdominal pain or bowel troubles in first-degree relatives was significantly associated with irritable bowel syndrome and dyspepsia. Whether the familial associations represent similar exposures in a shared environment, heightened familial awareness of GI symptoms (reporting bias), or genetic factors remains to be determined.