The value of pre-operative outpatient flexible sigmoidoscopy in patients with deep infiltrating endometriosis.

Background: Deep infiltrating endometriosis (DE) is a particularly severe disease which affects 10-20% of women with endometriosis. 90% of DE is rectovaginal and when suspected, some clinicians have suggested the routine use of flexible sigmoidoscopy to identify intraluminal disease. We aimed to assess the value of sigmoidoscopy prior to surgery for rectovaginal DE, both in terms of diagnosis and planning management. Objectives: We aimed to assess the value of sigmoidoscopy prior to surgery for rectovaginal DE. Materials and Methods: A retrospective case series study was performed from a consecutive cohort of patients with DE referred for outpatient flexible sigmoidoscopy between January 2010 and January 2020. All patients were under the care of a specialist endometriosis multidisciplinary team. Main outcome measures: The primary outcome measure was the incidence of luminal disease. Results: 102 consecutive cases were analysed with no cases confirming intraluminal disease. Non-specific evidence of endometriosis such as tight angulation of the bowel was found in 36.3%. Following sigmoidoscopy 100 patients proceeded to surgery and the risk of bowel resection during surgery was 4%. Conclusions: Due to the low incidence of luminal endometriosis, performing sigmoidoscopy routinely is of limited benefit. We recommend the selective use of sigmoidoscopy where serious pathology such as colorectal neoplasia is considered or to determine the location of endometriosis lesions which aids subsequent resectional surgery planning. What is new?: This large case series details a very low incidence of intraluminal disease and makes recommendations for the specific scenarios where flexible sigmoidoscopy should be used.