Endometriosis is the presence of endometrial glands and stroma at extrauterine sites. These ectopic endometrial implants are usually located in the pelvis but can occur nearly anywhere in the body. Endometriosis appears to be the most frequent cause of chronic pelvic pain in women of reproductive age and may cause prolonged suffering and disability that negatively affect health-related quality of life .
Rectovaginal or bowel involvement is estimated to be present in 5 to 12 percent of women with endometriosis . The rectosigmoid colon is the most common site of bowel endometriosis [2-5]. Bowel involvement typically coexists with disease at other sites. Thus, evaluation and management of colorectal disease must take into account full distribution of endometriotic lesions.
Bowel endometriosis can be thought of as two different entities, depending upon anatomic location: (1) rectovaginal endometriosis and (2) involvement of the bowel wall proximal to the rectosigmoid colon. Presenting symptoms, evaluation, and management differ somewhat for these two general locations.
Diagnosis and management of rectovaginal or bowel endometriosis are reviewed here. General principles of the treatment of endometriosis, as well as endometriosis of the urinary tract and thorax, are discussed separately. (See "Overview of the treatment of endometriosis" and "Urinary tract endometriosis" and "Thoracic endometriosis".)
OVERVIEW OF DISEASE CHARACTERISTICS
Pathogenesis — The three theories for the pathogenesis of endometriosis include: (1) spread of endometrial cells from retrograde menstruation; (2) lymphatic or hematogenous dissemination; and (3) coelomic metaplasia. (See "Pathogenesis, clinical features, and diagnosis of endometriosis", section on 'Pathogenesis'.)