To determine the prevalence, symptom pattern and impact of the irritable bowel syndrome, across eight European countries, using a standardized methodology. A community survey of 41 984 individuals was performed using quota sampling and random digit telephone dialing to identify those with diagnosed irritable bowel syndrome or those meeting diagnostic criteria, followed by in-depth interviews. The overall prevalence was 11.5% (6.2-12%); 9.6% had current symptoms, 4.8% had been formally diagnosed and a further 2.9%, 4.2% and 6.5% met the Rome II, Rome I or Manning criteria, respectively. Bowel habit classification varied by criteria: 63% had an 'alternating' bowel habit by Rome II vs. 21% by self-report. On average, 69% reported symptoms lasting for 1 h, twice daily, for 7 days a month. Irritable bowel syndrome sufferers reported more peptic ulcer (13% vs. 6%), reflux (21% vs. 7%) and appendectomy (17% vs. 11%), but not hysterectomy, cholecystectomy or bladder procedures. Ninety per cent had consulted in primary care and 17% in hospital; 69% had used medication. Irritable bowel syndrome substantially interfered with lifestyle and caused absenteeism. Irritable bowel syndrome is common with major effects on lifestyle and health care. The majority of cases are undiagnosed and the prevalence varies strikingly between countries. Diagnostic criteria are associated with varying prevalences and bowel habit sub-types. This limits their utility in clinical practice and the transferability of research findings using them.

The impact of irritable bowel syndrome, a gastrointestinal motility disorder, is underestimated and poorly quantified, as clinicians may see only a minority of sufferers. To determine the prevalence, symptom patterns and impact of irritable bowel syndrome in the US. This two-phase community survey used quota sampling and random-digit telephone dialing (screening interview) to identify individuals with medically diagnosed irritable bowel syndrome or individuals not formally diagnosed, but fulfilling irritable bowel syndrome diagnostic criteria (Manning, Rome I or II). Information on irritable bowel syndrome symptoms, general health status, lifestyle and impact of symptoms on individuals' lives was collected using in-depth follow-up interviews. Data were also collected for healthy controls identified in the screening interviews. The total prevalence of irritable bowel syndrome in 5009 screening interviews was 14.1% (medically diagnosed: 3.3%; undiagnosed, but meeting irritable bowel syndrome criteria: 10.8%). Abdominal pain/discomfort was the most common symptom prompting consultation. Most sufferers (74% medically diagnosed; 63% undiagnosed) reported alternating constipation and diarrhoea. Previously diagnosed gastrointestinal disorders occurred more often in sufferers than non-sufferers. Irritable bowel syndrome sufferers had more days off work (6.4 vs. 3.0) and days in bed, and reduced activities to a greater extent than non-sufferers. Most (76.6%) irritable bowel syndrome sufferers in the US are undiagnosed. Irritable bowel syndrome has a substantial impact on sufferers' well-being and health, with considerable socioeconomic consequences.

The prevalence of functional constipation is highly variable among epidemiological surveys and may relate to the definitions applied. We estimated the population prevalence of self-reported, Rome I-defined, and Rome II-defined constipation in Canada and determined the variables that best predicted health care seeking. A research firm was employed to conduct a random digit dial national survey, inviting household members at least 18 yr of age to participate in a study assessing personal health issues. The sample was stratified to ensure that each region of Canada was represented. Data collection involved three stages: 1) recruitment of participants by phone, 2) mailing of the questionnaire, and 3) data retrieval through a follow-up phone call. The Rome II questionnaire was used to derive the prevalence of functional constipation using both Rome I and Rome II criteria. Of the 1149 participants, 27.2% self-reported constipation within the past 3 months, and 16.7% and 14.9% had functional constipation according to Rome I and II, criteria, respectively. For all three definitions, the rate for women was close to twice that for men. Approximately 34% of those with self-reported constipation had visited a physician for it, versus 26.3% of Rome II subjects. In a regression model, subjects self-reporting in the past 3 months were more likely to have seen a doctor for their constipation (odds ratio 2.47, p < 0.01) and significantly more women than men (35.6% vs 19.5%, p < 0.05). Functional constipation and related health care seeking are common in the Canadian population and are strongly determined by the definition used. The Rome II criteria for this disorder seem to be satisfactory, but modifications may be considered to allow for constipated subjects taking laxatives and to increase the number of qualifying symptoms.