Does Bariatric Surgery Improve Faecal Incontinence? A Systematic Review and Meta-analysis.

INTRODUCTION: Obesity increases the risk of pelvic floor disorders in individuals with obesity, including faecal incontinence. Faecal incontinence (FI) is a condition with important clinical and psychosocial consequences. Though it is associated with obesity, the effect of bariatric surgery on the prevalence and severity of FI is not well reported. OBJECTIVE: To assess the effect of bariatric surgery on the prevalence and severity of FI in adult patients with obesity. METHODS: This systematic review was conducted in accordance with the PRISMA statement. Two independent reviewers performed a literature search in MEDLINE, PubMed, Cochrane and Embase from 1 January 1980 to 12 January 2019. We included published English-language randomized control trials and observational studies assessing pre- and post-bariatric surgery prevalence or severity of FI. Random-effects models with DerSimonian and Laird's variance estimator were used for meta-analysis. RESULTS: Thirteen studies were included, eight assessing prevalence (678 patients) and 11 assessing severity of FI (992 patients). There was no significant difference in prevalence post-operatively overall, though it trended towards a reduction [pooled OR=0.55; =0.075]. There was a significant reduction of FI prevalence in women post-bariatric surgery [95% CI 0.22 to 0.94, p=0.034]. There was a statistically significant reduction in FI prevalence following Roux-en-Y gastric bypass and one anastomosis gastric bypass [0.46, 95% CI 0.26 to 0.81; p=0.007]. There was no significant reduction of incontinence episodes post-operatively [pooled mean difference =-0.17, 95% CI -0.90 to 0.56; p=0.65]. Quality of life (QOL) was not significantly improved post-bariatric surgery [mean differences for the following facets of QOL: behaviour -0.35, 95% CI -0.94 to 0.24; depression 0.04, 95% CI -0.12 to 0.2; lifestyle -0.33, 95% CI -0.98 to 0.33; p values of 0.25, 0.61 and 0.33, respectively]. DISCUSSION: There was a significant reduction in FI prevalence in women and those who underwent Roux-en-Y or one anastomosis gastric bypass. Our results for FI prevalence overall, FI severity and impact on quality of life were not statistically significant. Larger studies are needed in this under-researched area to determine the true effect of bariatric surgery on FI.