Irritable Bowel Syndrome in the United States: Prevalence, Symptom Patterns and Impact

A. P. S. Hungin; L. Chang; G. R. Locke; E. H. Dennis; V. Barghout


Aliment Pharmacol Ther. 2005;21(11):1365-1375. 

In This Article

Summary and Introduction

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.
Aim: 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 dialling (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.

Irritable bowel syndrome (IBS) is a chronic, episodic functional gastrointestinal (GI) disorder characterized by abdominal pain/discomfort and altered bowel habit (constipation, diarrhoea or alternating periods of both).[1] Patients often experience additional symptoms such as bloating, sensation of incomplete evacuation, straining (constipation) and urgency (diarrhoea). IBS patients can experience symptoms for many years, with an average duration of 10 or more years.[1,2] IBS is often unrecognized or untreated, with as few as 25% of IBS sufferers seeking professional health care.[3] Those seeking care are often frustrated by the lack of effectiveness of traditional treatment and management strategies.[4]

IBS prevalence is estimated to be 10-15% in Western countries.[5,6,7,8,9] Prevalence data and information on the health care-seeking behaviour of IBS sufferers have mostly been derived from independent studies using different methodologies and different diagnostic criteria. As there are no IBS-specific biological markers to aid diagnosis, doctors generally rely on symptom-based criteria. At least three sets of diagnostic criteria have been developed, including the Manning,[10] Rome I[11] and Rome II criteria.[12] The Rome I and II criteria are more refined than the Manning criteria, and include symptom duration within their definitions. Variations in study design, particularly the criteria used to diagnose IBS, affect the ability to compare or summarize data from multiple studies.[13]

One challenge of population-based IBS studies is ensuring that IBS is accurately diagnosed using specific, validated criteria, rather than the clinical judgement of health care professionals.[7]

IBS places a significant financial burden on society. Symptoms can significantly impact on the quality of life of sufferers, with considerable socioeconomic consequences.[14,15,16,17,18] For example, absenteeism from work is more prevalent in individuals with IBS than in those without,[1,19] and employers in the United States (US) are estimated to pay, on average, $1251 more for individuals with IBS than matched control beneficiaries over a 1-year period ( P < 0.001).[20]

A recent European study investigated the prevalence, symptom pattern and impact of IBS across eight countries in an attempt to define the magnitude of the problem facing health care providers.[21] The present study, which used the same methodology, evaluated IBS prevalence, symptom pattern and impact on work, social activities and well-being of sufferers in the US. Attitudes towards the health and consultation behaviour of IBS sufferers were also assessed.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.