Supplementation with dietary fiber improves fecal incontinence

Human studies have shown that dietary fiber affects stool composition and consistency. Because fecal incontinence has been shown to be exacerbated by liquid stools or diarrhea, management strategies that make stool consistency less loose or liquid may be useful.

To compare the effects of a fiber supplement containing psyllium, gum arabic, or a placebo in community-living adults who were incontinent of loose or liquid stools. Mechanisms underlying these effects (e.g., fermentation of the fibers and water-holding capacity of stools) were examined.

Thirty-nine persons with fecal incontinence of loose or liquid stools prospectively recorded diet intake and stool characteristics and collected their stools for 8 days prior to and at the end of a 31-day fiber supplementation period. During the fiber supplementation period, they ingested psyllium, gum arabic, or a placebo by random assignment.

In the baseline period, the groups were comparable on all variables measured. In the fiber supplementation period, (a) the proportion of incontinent stools of the groups ingesting the fiber supplements was less than half that of the group ingesting the placebo, (b) the placebo group had the greatest percentage of stools that were loose/unformed or liquid, and (c) the psyllium group had the highest water-holding capacity of water-insoluble solids and total water-holding capacity. The supplements of dietary fiber appeared to be completely fermented by the subjects as indicated by nonsignificant differences in total fiber, short chain fatty acids and pH in stools among the groups in the baseline or fiber supplementation periods.

Supplementation with dietary fiber from psyllium or gum arabic was associated with a decrease in the percentage of incontinent stools and an improvement of stool consistency. Improvements in fecal incontinence or stool consistency did not appear to be related to unfermented dietary fiber.