A Randomized Pilot Study to Compare the Effectiveness of a Low FODMAP Diet vs Psyllium in Patients With Fecal Incontinence and Loose Stools

The aim of the study was to compare the effectiveness of a low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol diet (LFD) vs psyllium on the frequency and severity of fecal incontinence (FI) episodes in patients with loose stools. METHODS: This was a single-center, randomized pilot trial of adult patients with FI (Rome III) with at least 1 weekly FI episode associated with loose stool. Eligible patients were randomized to 4 weeks of either a dietitian-led LFD or 6 g/d psyllium treatment. RESULTS: Forty-three subjects were randomized from October 2014 to May 2019. Thirty-seven patients completed the study (19 LFD and 18 psyllium). There was no statistically significant difference in the proportion of treatment responders (>50% reduction in FI episodes compared with baseline) for treatment weeks 1–4 (LFD 38.9%, psyllium 50%, P = .33). Compared with baseline, mean fecal incontinence severity index score significantly improved with LFD (39.4 vs 32.6, P = .02) but not with psyllium (35.4 vs 32.1, P = .29). Compared with baseline values, the LFD group reported improvements in fecal incontinence quality of life coping/behavior, depression/self-perception, and embarrassment subscales. The psyllium group reported improvement in incontinence quality of life coping/behavior. DISCUSSION: In this pilot study, there was no difference in the proportion of patients who reported a 50% reduction of FI episodes with the LFD or psyllium. Subjects in the psyllium group reported a greater reduction in overall FI episodes, whereas the LFD group reported consistent improvements in FI severity and quality of life. Further work to understand these apparently discrepant results are warranted but the LFD and psyllium seem to provide viable treatment options for patients with FI and loose stools.