Therapy of rectal endometriosis is individually tailored to the patient and the progression of lesions. It should be a team approach composed of a surgeon and a gynecologist. Diagnosis of endometriosis and the start of the therapeutic process are usually associated with the existence of complications including obstruction, bleeding, perforation, or neoplastic transformation within a focus of endometriosis, which is much more common. Therapy of women with uncomplicated, symptomatic endometriosis is dependent upon the volume of the lesions, the patient’s age, and her attitude toward maternity [33, 48]. Surgical therapy should be considered in cases of existing pain, rectal bleeding, alterations in rectal structure, symptoms of incipient obstruction, and in cases of suspected neoplastic transformation, particularly if its exclusion is impossible.

In cases of symptomatic endometriosis in young women who would like to have children in the future and whose lesions are within certain size limits, laparoscopic resection may be considered with subsequent introduction of hormonal therapy. For several years, various authors have presented good outcomes of laparoscopic therapy of endometriosis in the rectum and the sigmoidorectal region consisting of partial or total resection of that section of the colon [76–82]. Postsurgical complications are reported in just 8–16 % of patients [79, 80, 82], with a conversion rate of 3.2–3.9 % [79, 80]. Recurrence in patients undergoing initial operations is observed in around 2–3.4 % [80, 83], and in cases of surgery for recurrent endometriosis the rate as high as 13.2 % (on average, about 8 %) [79]. However, laparoscopic techniques remain a challenge and constitute only an alternative therapy for foci of rectal endometriosis. Appropriate selection of patients and the surgeon’s experience are of great importance. Laparoscopic procedures may be difficult because of massive, dense adhesions, which, in our experience, occur more often than not. Laparoscopic procedures lacking the possibility of direct palpation during the separation of adhesions between the rectum and the vagina may lead to the dreaded formation of a rectovaginal fistula, which is reported in 3.2 % of patients [80]. With the laparoscopic technique it is necessary to perform a direct, rapid, intrasurgical, histopatological evaluation of the lesion. In those cases in which neoplastic transformation cannot be excluded, it is necessary to perform a laparotomy and a broad resection of the tumor with its surrounding tissues en bloc.

The obliteration of the pouch of Douglas is laparoscopically pathognomonic of pelvic endometriosis [84]. Although laparoscopic resection in colorectal endometriosis is feasible, it is technically challenging and can be used in only select cases [85]. Those patients who wish to get pregnant after endometriosis surgery should be informed that about 40 % of infertile women will be able to coneceive after laparoscopic surgery, although the spontaneous pregnancy rate in laparoscopically treated patients is slightly higher than those who have undergone open surgery. The likelihood of fertility over time with a successful pregnancy is reduced if open colorectal resection is performed (as opposed to simple laparoscopic treatment without resection) and if there is coincident adenomyosis, so the patient groups are not strictly comparable [86]. Urinary and bowel dysfunction are less likely to occur with laparoscopic treatment if nodule excision of colorectal lesions is performed rather than colorectal resection, but these patients often cannot be adequately stratified [87].

The basic surgical procedures used in the therapy of endometriosis include anterior resection of the rectum with primary anastomosis or anterior resection with formation of sigmoidostomy or colostomy. Much less common is local excision of the anterior rectal wall with introduction of ­hormonal therapy, which is performed in cases of young patients who want to give birth in the future and who do not accept total resection of the rectum as an option [33, 48]. Anterior resection of the rectum with primary anastomosis is performed most often. Numerous authors have presented good outcomes of that procedure over a long time period [25, 48, 83]. The procedure is completed after preparation of the colon similar to that done for any other colorectal operation in that region. What should be considered carefully during the procedure is the removal of all endometrial implants within a single tissue block. Dissection of the rectovaginal septum area is often extremely difficult because of advanced scarring, dense adhesions, and inflammatory infiltration. Operative dissection in that area may be facilitated by simultaneous gynecological examination with compression of the posterior vaginal wall. Anterior rectal resection is completed in the typical manner by preparing the posterior wall of the vagina up to distal soft, nonaltered tissue as confirmed by palpation [48] and is a distinct advantage in these difficult cases of the open approach.

In cases of young patients who want to give birth in the future, hormonal therapy is used after surgery to eliminate residual foci that are not visible to the eye and to prevent recurrence [33, 48, 88]. The therapy involves the combined administration of estrogen and progesterone or progesterone or danazol alone. The use of analogue hormones resulting in the release of luteinizing hormone and aromatase inhibitors also is recommended, with reported reductions in both menstrual and nonmenstrual pain as well as dyschezia [89]. Although hormonal therapy is successful and recommended for reduction of endometrial tissue, one should consider that old, fibrous, scarred, and nonactive foci of endometriosis do not respond to hormonal stimulation [90]. Hormonal therapy alone may transform endometrium into fibrous tissue, causing exacerbation of rectal stenosis and enteral symptoms [32]. In the case of women of peri- and postmenopausal age, an extension of surgery should be considered, with a total abdominal hysterectomy and bilateral salpingo-oophorectomy. That procedure removes a source and the pathological route of dissemination for endometriosis. In the event of such aggressive therapy with excision of the rectal endometriosis and simultaneous total abdominal hysterectomy/salpingo-oophorectomy, good long-term, recurrence-free outcomes have been observed in 94 % of cases, compared with a 77 % recurrence-free rate in cases where the ovaries have been conserved [91].

Endometriosis of the rectum, similar to endometriosis of the entire alimentary tract, is not a common condition. The most appropriate methods of conduct in relation to those cases, including clear indications of surgery, recommended surgical methods, and extension of resections, have not been clearly defined. However, surgical treatment of endometriosis with complete resection of pathologically altered bowel is advised because of the possible development of malignancy within these lesions [10, 46]. Such a selected policy is ­associated with acceptable symptom outcomes, fertility, and pregnancy rates and in many cases an improvement in quality of life parameters [92].