Jeremy Meyers interviews Dr Alexandre Balaphas on the prevalence of anal incontinenceJM AB

Dr Alexandre Balaphas (right) is junior consultant surgeon in the Neuchâtel Hospital Network, Switzerland. He trained in digestive surgery at the University Hospitals of Geneva, Switzerland, where he had the privilege to work with Prof Frédéric Ris and Prof Bruno Roche. He obtained a MD-PhD degree in the field of cell therapies at the University of Geneva. His current work focuses on the application of cell therapies for treating anal incontinence, and he was recently awarded with the Sir Jules Thorn Foundation Charitable Overseas Trust to bring his research to a pre-clinical level.

Jeremy Meyer (JM): Thank you Dr. Balaphas for sharing with us your expert view on the prevalence of anal incontinence as primary lead of the ANUS (Anal incontiNence Prevalence in a University hospital Staff) study.

Alexandre Balaphas (AB): Thank your Dr. Meyer for your kind invitation.

JM: The estimation of the prevalence of anal incontinence suffers from several bias and, until now, the true prevalence of anal incontinence has remained a matter of debate. Could you please tell us more about the literature in the field?

AB: Beside the bias related to the taboo of anal incontinence, there is also a problem of definition. I am glad that you used the term “anal incontinence”. Indeed, medical world is largely using the term “fecal incontinence” which, by definition, underestimates the prevalence of the disease. This is well illustrated by the Rome foundation criteria, focusing only on stool incontinence. I believe that the less morbid incontinence to flatus should also be considered, as it can be connected to a specific pathology and/or precede incontinence to feces. Anal incontinence is a term that encompasses both incontinence to flatus and incontinence to feces.

Because of this lack of consensus and criteria for anal incontinence, studies led by surgeons are usually using the Jorge-Wexner score to evaluate anal incontinence. While largely used for research, the Jorge-Wexner score was not designed for this purpose and is certainly not suited for the diagnostic of anal incontinence. As a results of all these factors, the reported prevalence of anal incontinence in the literature ranges from 0.4% to 24%.

JM: What was your initial motivation in undertaking a study aiming at determining the true prevalence of anal incontinence?

AB: I think that before treating a condition, especially with invasive procedures, it is worth to have a good understanding of its pathophysiology and its epidemiology. Would you treat an infectious disease with antibiotics without having a clear diagnostic definition and information about its prevalence, even approximatively? For anal incontinence, its prevalence ranged from a rare condition to a very common one. I hope this will open the debate about all these issues.

JM: To determine the prevalence of anal incontinence, you targeted healthcare workers. Can you explain why?

AB: We targeted the workers of a tertiary hospital who constitutes a pool of participants sensitized to health issues that could genuinely answer to our query. Our collaborators were invited to answer to a questionnaire that was sent to their professional mailbox. All the process was completely anonymous.

JM: How did you select the scales for quantifying anal incontinence?

AB: To compensate the lack of consensus about the definition of anal incontinence, we chose to use different definitions and scale. Statistics were ran using these different outcomes and compared.

JM: And what results have you found? What is the prevalence of anal incontinence in this population?

AB: Among the 14’279 collaborators of our hospital, 2’532 participants filled the questionnaire (17.7%). This sample was representative of the total hospital staff regarding age, gender and occupation (when compared to official demographic statistics). Twenty-nine percents of the participants reported occasional episodes of anal incontinence (more than once a month but less than once a week). The Jorge-Wexner score was ≥ 3 in 20.9% of the participants and 15% reported rare episodes of fecal incontinence. However, only 2.3% fulfilled the strict Rome IV criteria for fecal incontinence. A difference between women and men regarding the presence of anal incontinence was found (32.2 % versus 21% p <0.001) but was not statistically significant for Rome IV criteria. In women, vaginal delivery was not associated with anal incontinence in univariate and multivariate analyses or with Rome IV criteria after adjustment. On the other hand, diabetes was strongly associated with Rome IV criteria (OR: 3.3, 95% CI: 1.09-10.08, p= 0.035). History of proctological procedure was also significantly and strongly associated with anal incontinence and Rome IV criteria (OR: 4, 95% CI: 1.86-8.6, p<0.001).

JM: Were these results expected?

AB: Our results regarding the prevalence of anal incontinence were higher than expected but similar to a study performed by Santacruz et al. on their own hospital staff and on a smaller sample (415 participants). However, the poor association between childbirth and anal incontinence was unexpected, as vaginal delivery constitutes a classical etiology found in all textbooks.

JM: What conclusion do you draw from your results?

AB: Anal incontinence seems to be a common condition, even in apparently healthy and active individuals. On the other hand, recurrent episodes of fecal incontinence (ROME IV criteria) seem to be less prevalent in the studied population. Moreover, the association between childbirth and anal incontinence deserves further investigations.

JM: Do you think that your results will lead to a change of practice?

AB: I hope that this work will highlight the necessity of a true definition of anal incontinence and the recognition of flatus incontinence as being linked to fecal incontinence in a disease called anal incontinence. A clarification of these definitions could clearly benefit to patient that could be identified early in the evolution of their anal incontinence. I also think that the physiopathology and etiology of anal incontinence should be revisited. For instance, the healing process after sphincter lesion (such as a childbirth tear) or the effect of aging on anal sphincters have been poorly investigated until know.

JM: Thank you so much for sharing your knowledge with us, and again, congratulations for your impressive dedication to functional disorders in colorectal surgery, both clinically and fundamentally.

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