Is endometriosis associated with irritable bowel syndrome? A cross-sectional study

OBJECTIVES: Previous studies have found a high prevalence of irritable bowel syndrome (IBS). However, data on this relation in women without bowel endometriosis is limited. The aim of this study was to compare the prevalence of IBS in women with endometriosis to the prevalence in women without endometriosis and to investigate if the prevalence of IBS was associated with bowel involved endometriosis. STUDY DESIGN: Information for this cross-sectional study was collected through an online questionnaire. A total of 373 women completed the questionnaire. After exclusions, 254 with endometriosis and 102 without endometriosis were included (N = 356). Endometriosis was identified by self-reported diagnosis. IBS was identified by; 1. self-reported diagnosis prior to the study and 2. fulfillment of ROME III diagnostic criteria in this study. Odds ratios were calculated to estimate the strength of the association between IBS and endometriosis. A separate analysis, restricted to women without bowel involved endometrioses, was conducted. Adjustment for potential confounders (age, gastroenterological comorbidities and length of education) was performed. RESULTS AND CONCLUSIONS: The prevalence of IBS was higher in women with endometriosis compared to the women without endometriosis (OR = 5.32 (CI: 2.88; 9.81)). In the analysis restricted to women without bowel involved endometriosis, the prevalence was also higher in women with endometriosis compared to women without endometriosis (OR = 6.54 (CI95% 3.22; 13.29)). Thus, this study found a higher prevalence of IBS in women with endometriosis compared to women without endometriosis. This finding seems to be unrelated to bowel involvement. This opens new perspectives in relation to treatment of endometriosis.