Background: While the association between obesity and urinary incontinence (UI) in women has been clearly documented, the relationship with anal incontinence (AI) is less well defined; moreover, while bariatric surgery has been shown to improve UI, its effect on AI is still unclear.
Methods: A total of 32 obese women were studied by means of PFDI-20 and PFIQ-7 questionnaires and anorectal manometry before and after bariatric surgery and compared with 71 non-obese women.
Results: Obese women showed worse overall questionnaire results (OR 5.18 for PFDI-20 and 2.66 for PFIQ-7). Whereas obese women showed worse results for urinary sub-items and a higher urge UI incidence (43.8 vs 18.3 %, p = 0.013), they did not show worsening in colorecto-anal symptoms. Post-operatively, median PFDI-20 total score did not change (24.2 vs 26.6, p = ns), while there was an improvement in urinary score (14.6 vs 8.3, p < 0.001); median PFIQ-7 improved (4.8 vs 0.0, p = 0.044), but while the urinary score improved (2.4 vs 0.0, p = 0.033), the colorecto-anal score did not change significantly. Although after surgery urge UI decreased from 43.8 to 15.6 % (p = 0.029), the incidence of any AI increased from 28.1 to 40.6 % (p = ns) and flatus incontinence increased from 18.8 to 37.5 % (p = ns). Anorectal manometry did not show significant changes after surgery.
Conclusions: Obese women had worse questionnaire results, but while showing a higher incidence of UI, they did not experience anorectal function worsening. After bariatric surgery, there was a slight improvement in PFD symptoms related to UI, but anorectal function did not change significantly and flatus incontinence increased.