A Retrospective Investigation on Electric Bidet Use as a Possible Cause of Anal Incontinence

OBJECTIVES: The present study aimed to explore whether symptoms of anal incontinence (AI) in patients who used electric bidet toilets to clean the anus may improve after discontinuing bidet use. METHODS: Fifty-three patients with AI who habitually used the bidets before or after defecation and were examined between June 2019 and September 2020 were included in this retrospective study. Questionnaires on Likert-scaled items that assessed bidet use were administered at baseline. The sum of all points was regarded as the “bidet use score”. The patients were instructed to discontinue bidets until subsequent examination. Incontinence severity was documented using the fecal incontinence severity index (FISI) score. RESULTS: Follow-up data were available for 49 patients (92%). Of those, 43 had fecal incontinence and 6 had only mucus discharge at baseline. The median duration between the baseline and follow-up was 4 weeks. The median FISI score was significantly reduced at the follow-up [baseline vs. follow-up: 15 (range: 3-43) vs. 10 (range: 0-43); P < 0.0001]. The incidence of fecal incontinence was significantly lower at the follow-up than at the baseline (59% vs. 88%, P = 0.003). A higher maximum squeeze pressure and the absence of associated factors that may cause AI (such as rectoanal intussusception and/or rectocele, mucosal prolapse, and previous anorectal surgery) were significantly associated with a reduction of at least 50% in the FISI scores at follow-up; however, this was not observed for the bidet use score. CONCLUSIONS: Our findings suggest that electric bidet use is a possible cause of AI.