Dietary fiber supplementation for fecal incontinence: a randomized clinical trial.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 25155992 · doi:10.1002/nur.21616
What was done
A single-blind randomized controlled trial compared three dietary fiber supplements with differing fermentability (carboxymethylcellulose [CMC], gum arabic [GA], and psyllium) against placebo in 189 community-dwelling adults with fecal incontinence (FI) of loose or liquid feces. Following a 14-day baseline, participants consumed placebo or 16 g total fiber/day of one of the supplements for 32 days. The primary outcome was FI frequency. Secondary outcomes included FI amount and consistency, supplement intolerance, quality of life (QoL), and fecal gel formation.
What was found
Psyllium significantly decreased FI frequency compared to placebo in both intent-to-treat and per-protocol mixed model analyses, whereas CMC increased FI frequency. In intent-to-treat analysis, estimated post-supplementation FI episodes per week were 2.5 for Psyllium, 4.3 for GA, 5.5 for Placebo, and 6.2 for CMC. Fecal gel formation occurred exclusively with psyllium. Supplement intolerance was low across arms, and QoL scores showed no statistically significant differences between groups.
Why it matters
Shows that fiber efficacy in loose-stool fecal incontinence depends on fiber type, with psyllium halving weekly episode frequency through fecal gel formation while non-gel-forming fibers like CMC may worsen symptoms.
Limits
The trial was single-blind rather than double-blind, creating potential reporting bias. The intervention period was short (32 days), and the intervention did not produce detectable improvements in overall quality-of-life scores during that timeframe.
Cited by
- supports Fiber supplements such as psyllium improve rectal sensitivity and reduce the frequency of fecal incontinence episodes.