BACKGROUND: Well designed, large comparative effectiveness trials assessing the efficacy of primary interventions for faecal incontinence are few in number. The objectives of this study were to compare different combinations of anorectal manometry-assisted biofeedback, loperamide, education, and oral placebo.
METHODS: In this randomised factorial trial, participants were recruited from eight clinical sites in the USA. Women with at least one episode of faecal incontinence per month in the past 3 months were randomly assigned 0·5:1:1:1 to one of four groups: oral placebo plus education only, placebo plus anorectal manometry-assisted biofeedback, loperamide plus education only, and loperamide plus anorectal manometry-assisted biofeedback. Participants received 2 mg per day of loperamide or oral placebo with the option of dose escalation or reduction. Women assigned to biofeedback received six visits, including strength and sensory biofeedback training. All participants received a standardised faecal incontinence patient education pamphlet and were followed for 24 weeks after starting treatment. The primary endpoint was change in St Mark's (Vaizey) faecal incontinence severity score between baseline and 24 weeks, analysed by intention-to-treat using general linear mixed modelling. Investigators, interviewers, and outcome evaluators were masked to biofeedback assignment. Participants and all study staff other than the research pharmacist were masked to medication assignment. Randomisation took place within the electronic data capture system, was stratified by site using randomly permuted blocks (block size 7), and the sizes of the blocks and the allocation sequence were known only to the data coordinating centre. This trial is registered with ClinicalTrials.gov, number NCT02008565.
FINDINGS: Between April 1, 2014, and Sept 30, 2015, 377 women were enrolled, of whom 300 were randomly assigned to placebo plus education (n=42), placebo plus biofeedback (n=84), loperamide plus education (n=88), and the combined intervention of loperamide plus biofeedback (n=86). At 24 weeks, there were no differences between loperamide versus placebo (model estimated score change -1·5 points, 95% CI -3·4 to 0·4, p=0·12), biofeedback versus education (-0·7 points, -2·6 to 1·2, p=0·47), and loperamide and biofeedback versus placebo and biofeedback (-1·9 points, -4·1 to 0·3, p=0·092) or versus loperamide plus education (-1·1 points, -3·4 to 1·1, p=0·33). Constipation was the most common grade 3 or higher adverse event and was reported by two (2%) of 86 participants in the loperamide and biofeedback group and two (2%) of 88 in the loperamide plus education group. The percentage of participants with any serious adverse events did not differ between the treatment groups. Only one serious adverse event was considered related to treatment (small bowel obstruction in the placebo and biofeedback group).
INTERPRETATION: In women with normal stool consistency and faecal incontinence bothersome enough to seek treatment, we were unable to find evidence against the null hypotheses that loperamide is equivalent to placebo, that anal exercises with biofeedback is equivalent to an educational pamphlet, and that loperamide and biofeedback are equivalent to oral placebo and biofeedback or loperamide plus an educational pamphlet. Because these are common first-line treatments for faecal incontinence, clinicians could consider combining loperamide, anal manometry-assisted biofeedback, and a standard educational pamphlet, but this is likely to result in only negligible improvement over individual therapies and patients should be counselled regarding possible constipation.
FUNDING: Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institutes of Health Office of Research on Women's Health.