Prevalence of irritable bowel syndrome in the French population according to the Rome I criteria

Irritable bowel syndrome (IBS) is a common functional gastro-intestinal disease. In the absence of specific markers, definition and hence diagnosis depend on clinical presentation. Of the various attempts to set criteria for IBS, the most recent are Rome I and Rome II classifications.

To estimate in a general population the prevalence of IBS using the modified Rome I criteria, and to investigate socio-demographic criteria, symptoms and management.

A total of 11,131 people aged 18 years and over, representative of the French population, were surveyed. A diagnostic questionnaire based on the modified Rome I criteria was used to identify IBS sufferers, who were then questioned further about the symptoms and medical management of their IBS.

Of the 5,299 men and 5,832 women interviewed, 445 had IBS according to the Rome I criteria, a prevalence of 4% (95% CI: 3.6%-4.4%). IBS was more frequent in women (5.3%) than in men (2.5%), with a sex ratio (F/M) of 2.3. In 9.1% of sufferers, onset had occurred less than 12 months ago, a yearly incidence of 3.6 per 1,000 of the population. In 32.3% of IBS sufferers diarrhoea was predominant, and in 34.6% constipation was predominant. Of IBS sufferers 83.7% had consulted a physician for their condition, and 87.6% had taken medication for their IBS symptoms over the previous 12 months.

The prevalence of IBS observed in this study in France was close to the lower limit in published data (3 to 20%). Our results suggest that the Rome I criteria are not sensitive enough to detect all IBS patients in a population not actively seeking health care intervention for the condition. In this regard, the refined classification (Rome II) which was established after our study was carried-out should be evaluated.