The aim of this study was to evaluate progression of the bowel endometriosis lesion over time. We performed a retrospective cohort with 164 patients with rectosigmoid endometriosis identified by transvaginal ultrasound (TVUS) with bowel preparation waiting for surgical treatment. Length and circumference of the bowel lesion evaluated by TVUS, painful symptoms (dysmenorrhea, dyspareunia, noncyclic pelvic pain, dyschezia, dysuria), and menopausal status were assessed at baseline and 6, 12, 24, 36, and > 36 months. A linear mixed model was used and p values < 0.05 were considered significant. We considered the length and the circumference as the main parameter; the characteristics were considered as fixed effects and the patient as random effect. This model allows to deal with missing data from longitudinal studies. All painful symptoms significantly improved during follow-up. Overall, the mean length and circumference of the greatest bowel lesion were 2.9 ± 1.8 cm and 27 ± 10%, respectively, and those did not change over time (p > 0.05). Patients with severe dyspareunia had significant greater circumference (p = 0.037) and those with severe dyschezia had significant greater length (p = 0.047) of bowel lesions. Symptoms were not related with progression of the lesion over time. The bowel lesion length significantly decreased over time in patients in menopause (p = 0.009). There was no difference in the bowel lesion length between patients with and without hormonal treatment (p > 0.05). The results suggest that bowel endometriosis does not increase over time during reproductive age and reduces after menopause. Symptoms are also not related to the bowel lesion progression.
Keywords: Bowel endometriosis; Deep endometriosis; Disease progression; Hormonal treatment; Transvaginal ultrasound.