Increased Long-term Dietary Fiber Intake Is Associated With a Decreased Risk of Fecal Incontinence in Older Women.

Abstract

Fiber supplements are frequently used as treatment for fecal incontinence (FI), but little is known about the role of dietary fiber in the prevention of FI. We performed a prospective study to examine the association between long-term dietary fiber intake and risk of FI in 58,330 older women (mean age, 73 years) in the Nurses' Health Study who were free of FI in 2008. Energy-adjusted long-term dietary fiber intake was determined using food frequency questionnaires starting in 1984 and updated through 2006. We defined incident FI as at least 1 liquid or solid FI episode per month during the past year during 4 years of follow-up using self-administered biennial questionnaires. We used Cox proportional hazards models to calculate multivariable-adjusted hazard ratios and 95% CIs for FI according to fiber intake, adjusting for potential confounding factors. During 193,655 person-years of follow-up, we documented 7,056 incident cases of FI. Compared with women in the lowest quintile of fiber intake (13.5 g/day), women in the highest quintile (25 g/day) had an 18% decrease in risk of FI (multivariable hazard ratio, 0.82; 95% CI, 0.76-0.89). This decrease appeared to be greatest for risk of liquid stool FI, which was 31% lower in women with the highest intake of fiber compared with women with the lowest intake (multivariable hazard ratio, 0.69; 95% CI, 0.62-0.75). Risk of FI was not significantly associated with fiber source. In an analysis of data from almost 60,000 older women in the Nurses' Health Study, we found higher long-term intake of dietary fiber was associated with decreased risk of FI. Further studies are needed to determine the mechanisms that mediate this association.