A large US national epidemiological study of constipation

Abstract

Introduction: Published estimates of the prevalence of constipation vary widely, due, in part, to variation in case definitions used and survey methods. The study was conducted to obtain detailed data on a broad spectrum of lower GI symptoms in the US population. The objective of this study was to estimate the prevalence of constipation and clinical subtypes and determine if subtypes differed by sociodemographic factors. Methods: Between June, 1997 and September, 1997, 10,018 individuals 18 years of age and older completed a telephone interview about bowel habits and constipation-related symptoms. A total of 69% of the eligible individuals who were contacted agreed to participate. The recall period for reporting symptoms was the 3 months before the interview. Interview data on 15 constipation-related symptoms were used to identify individuals who met a priori symptom criteria for functional constipation (e.g., Rome criteria), IBS constipation (e.g., Rome), outlet obstruction (e.g., Talley et al), and selfreported constipation (i.e., self-reported and not in one of the other 3 groups). Results: The prevalence of constipation for all subtypes combined was estimated at 28%. By subtype, the prevalence was 8% for functional constipation (FC), 9% for IBS constipation (IBS), 6% for outlet obstruction (OD), and 5% for self-reported constipation (subjects who did not meet criteria for the other subtypes). Prevalence of constipation subtypes differed in their association with sociodemographic factors. In particular, the female to male (F/M) gender ratio was lowest for FC (F/M=0.86) and elevated for OD (F/M=I.5) and IBS (F/M=2.0). Prevalence decreased with increasing age, especially for FC and IBS. Prevalence of FC appears to increase with increasing education. OD was more common among non-Whites compared to Whites. Forty percent of individuals with constipation reported having the condition for 5 years or more. Conclusions: Data from this study indicate that constipation is a common chronic condition affecting approximately 55 million people in the US. Evidence from this study indicates that constipation subtypes vary to some degree by sociodemographic factors. Finally, these data suggest that both FC and OD may have been substantially underestimated in previous studies. This study was supported by Janssen Research Foundation, Titusville, NJ