Endometriosis is as chronic gynaecological condition in which there is endometrial tissue outside uterus and induces chronic inflammatory condition. Deep endometriosis is defined as endometriosis 5 mm beneath the peritoneum. This type of endometriosis is mostly found on the uterosacral ligaments, inside the rectovaginal septum or vagina, in the rectosigmoid area, ovarian fossa, pelvic peritoneum, ureters, and bladder, causing a distortion of the pelvic anatomy. Endometriosis affects the bowel in 3%-37% of all case, and in 90% of these cases the rectum or sigmoid colon are also involved.The term “bowel endometriosis” should be used when endometrial-like glands and stroma infiltrate the bowel wall reaching at least the subserous fat tissue or adjacent subserous plexus

Symptoms of Bowel Endometriosis:

Most common symptoms is pelvic pain and infertility.

Bowel symptoms

Alterations of bowel habits such as constipation,

Diarrhea,

Tenesmus,

Dyschezia,

rarely, rectal bleeding

Differential diagnosis

Differentials can vary from Irritable bowel syndrome to Solitary rectal ulcer syndrome and a rectal tumor. Although colonic endometriosis may be asymptomatic, it can also present as large bowel obstruction. Colonic endometriosis must be differentiated from Crohn’s disease, diverticular disease, adhesions, or neoplasm. Also for small bowel implants secondary to endometriosis, difficulty exists to differentiate this condition from Crohn’s disease, because a similar endoscopic and histologic image can be seen. Intestinal perforation due to endometriosis may occur in the colon and also in an appendix with transmural endometriosis.

Diagnosis and pre-operative work up.

Preoperative work-up is essential in planning a multidisciplinary surgical treatment an. Precise diagnosis is necessary with regard to location and extent of bowel endometriosis. For the evaluation of bowel endometriosis, with or without involvement of the rectovaginal septum, transvaginal ultrasonography, barium enema examination, and magnetic resonance imaging (MRI) are the imaging techniques of choice. These technical investigations should aim to: (1) document the extent of the disease; (2) help in planning a multidisciplinary treatment; and (3) counsel patients regarding postoperative complications.

DE can be detected as a heterogeneous, hypo-echoic, and sometimes spiculated mass. According to a recent meta-analysis, bowel endometriosis can be diagnosed by transvaginal ultrasound with pooled estimates of sensitivity and specificity of 91% and 98%, respectively. If bowel endometriosis is suspected, a barium enema examination is performed to investigate the extent of the disease. Deep invasion of the bowel wall appears as an extrinsic mass compressing the bowel lumen in association with fine crenulation of the mucosa in this particular region. Also, bowel strictures at the rectosigmoid junction can be seen.

Management of Bowel Endometriosis

Indication of surgicical intervention in severe endometriosis include  severe, incapacitating symptoms not responsive to medical therapy or the presence of advanced disease indicated by anatomic distortion of pelvic organs or partial bowel obstruction. When preparing for a surgery to evaluate potential endometriosis, the patient should be consented not only for a diagnostic procedure but also for synchronous ablation or excision of endometriotic implants and adhesions. Laparoscopy is the procedure of choice for the diagnosis and treatment of endometriosis including disease affecting the bowel. A recent randomized trial of laparoscopically assisted versus open colorectal resection for endometriosis found that laparoscopy was equally safe and offered a higher pregnancy rate with similar improvements in symptomotology and quality of life.

Surgical Management

Surgical Management of laparoscopic endometriosis needs multidisciplinary approach which includes both surgeons as well as gynecologist. The first reported laparoscopic colon resection for endometriosis was performed in 1989,since that time minimally invasive techniques to treat intestinal endometriosis have been increasingly utilized with favorable results.

Laser Ablation

Use of the CO2 laser for treatment of deep rectosigmoid colon and rectovaginal septum endometriosis was reported as early as 1992 by Nezhat. A randomized trial of CO2 laser laparoscopic treatment of minimal, mild and moderate endometriosis, although not specific to intestinal endometriosis, established this modality as a safe, simple and effective treatment.  A subsequent retrospective study of CO2 laser laparoscopic excision of deep endometriosis with colorectal extension demonstrated a reduction in pain while improving quality of life.Post operative complications and recurrence rates were relatively low. The cumulative pregnancy rate was 31 and 70% at 1 and 4 years after surgery respectively.

Shave Excision

Superficial rectovaginal endometriosis can be shaved off the rectal wall while leaving the mucosa intact.The most distal peritoneal attachments of the rectum on both the anterior and lateral aspects are incised to enable access to the extraperitoneal rectovaginal septum. The endometrial implant is then dissected free from the anterior rectal wall and the posterior vaginal wall. The extraperitoneal rectal wall lacks the outer serosal lining and is comprised of mucosa, submucosa, muscularis propria and peri-rectal fat. If the dissection is maintained as superficial then bowel integrity will not be compromised. By contrast, if the dissection requires resection of a portion of the muscularis propria, the surgeon should reinforce any defect with laparoscopically placed sutures to diminish the risk of postoperative bowel perforation. Mechanical or thermal damage to the mucosa should be avoided. Visual inspection with proctoscopy after completion of the excision and an air leak test can ensure that no inadvertent proctotomy exists.

Anterior Disk Excision (open)

Deeper lesions of the intestinal wall may require full thickness excision yet not require a full segmental resection. For example, an infiltrating lesion located in the anterior aspect of the rectum may be treated by local full thickness excision. The excision can be performed with the aid of electrocautery or CO2 laser after adequate laparoscopic mobilization of the rectum. The bowel is then repaired by laparoscopic suturing or with the aid of an endo linear stapling device. The repair should be made in the transverse axial plane so as to prevent narrowing and potential stricture of the bowel lumen.

Anterior Disk Excision (closed)

An alternative approach to disk excision allows for use of a circular stapler, introduced transanally, to remove a full thickness patch of the anterior rectal wall.This procedure is appropriate for anterior rectal endometriosis that occupies less than one third of the circumference of the rectal wall and is less than 2 centimeters in diameter.