Impact of irritable bowel syndrome: prevalence and effect on health-related quality of life.

The prevalence of a disease and its effect on health-related quality of life (HRQOL) are important measures of its burden on society. The prevalence of irritable bowel syndrome (IBS) symptoms in the U.S. general population is approximately 10%, with lower estimates of prevalence if IBS is defined according to the more restrictive Rome II criteria. In population-based studies, there are no large differences in the prevalence of IBS symptoms between men and women or among the three major symptom subtypes of IBS (diarrhea- or constipation-predominant or alternating). However, the majority of persons with IBS-like symptoms do not seek care for these symptoms and, in those who do seek care, there is a 2-to-1 female-to-male predominance. HRQOL is an important measure that should be considered in the overall assessment of a largely subjective, nonfatal disease such as IBS. Studies that have measured HRQOL in IBS used generic instruments, mostly the 36-Item Short Form Health Survey, and few have used IBS-specific instruments. In a systematic review of the literature, there is strong evidence that persons with moderate to severe IBS who seek care for their symptoms (consulters) show decreased HRQOL. The impact of IBS on HRQOL in nonconsulters is less clear. Finally, a therapeutic response in IBS-related symptoms corresponds with an improvement in HRQOL.