Irritable bowel syndrome in the United States: prevalence, symptom patterns and impact.
BACKGROUND
The impact of irritable bowel syndrome, a gastrointestinal motility disorder, is underestimated and poorly quantified, as clinicians may see only a minority of sufferers.


OBJECTIVE
To determine the prevalence, symptom patterns and impact of irritable bowel syndrome in the US.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Hungin
A P S
AP
Centre for Integrated Health Care Research, Wolfson Research Institute, University of Durham, Stockton-on-Tees, UK. a.p.s.hungin@durham.ac.uk
Chang
L
L
Locke
G R
GR
Dennis
E H
EH
Barghout
V
V
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D001294:Attitude to Health; D005260:Female; D006295:Health Resources / Q000706:statistics & numerical data; D006304:Health Status; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000453:epidemiology*; D008019:Life Style; D008297:Male; D008875:Middle Aged; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data; D015995:Prevalence; D014481:United States / Q000453:epidemiology