Patients with irritable bowel syndrome are more burdened by co-morbidity and worry about serious diseases than healthy controls--eight years follow-up of IBS patients in primary care.

Background: Irritable Bowel Syndrome (IBS) is a hidden public health disease that affects up to 20% of the general population. Although co-morbidity can affect diagnose setting and treatment of the disease, there are few studies concerning diagnosed and registered co-morbidity for IBS patients in primary care. The aim of this study was to analyse co-morbidity among IBS-patients compared to age- and sex-matched controls from the general population using data from a county-wide computerized medical record system.

Methods: IBS cases were recruited from three Swedish primary health care centres during a five-years period and controls from the same corresponding geographical areas. Co-morbidity data for IBS-patients and morbidity data for controls were derived from a population-based Health Care Register (HCR) covering all diagnoses in primary as well as hospital care in the region. Odds Ratios with 95% confidence intervals for morbidity in gastro-intestinal and non-gastrointestinal diagnoses for cases with irritable bowel syndrome compared to controls were calculated separately for each gender and diagnosis.

Results: We identified more co-morbidity among IBS patients of both sexes, compared to matched controls in the general population. Patients with IBS were particularly more worried about having a serious disease than their control group. The risk among male IBS-cases to get this latter diagnose was three times higher compared to the male controls.

Conclusions: In this population based case-control study, the analysis of diagnoses from the HCR revealed a broad spectrum of common co-morbidity and significantly more physician-recorded diagnoses among IBS-patients in comparisons to the control group.