Bowel Endometriosis

Endometriosis of the bowels is a special entity which requires a high index of awareness and suspicion for correct diagnosis, and expertise for management.

Many women who suffer from endometriosis may not realise that the disease can affect the bowels. This may be due to:

  • the fluctuating nature of symptoms
  • a lack of awareness of the link between bowel symptoms and endometriosis
  • or inadequate appreciation of the extent of the disease at laparoscopy

How common does endometriosis affect the bowels and where?

The exact incidence is unclear but may occur in 5-15% of all cases of endometriosis. The sites where endometriosis occurs are the rectum, the sigmoid, the appendix and the small bowels.

What are the symptoms of bowel endometriosis?

Women with bowel endometriosis may present with pain related to periods, pain on intercourse and /or on bowel movements. Other symptoms may include cyclical abdominal bloating, constipation or diarrhea. Rectal bleeding is uncommon. Some women may present with infertility while others may have few or no symptom.

How can bowel endometriosis by diagnosed?

Diagnosis of bowel endometriosis requires a careful history and thorough physical examination. The detection of tender nodule at the top of the vagina adjacent to the rectum should raise suspicion. Women found to have ovarian endometriotic cysts on ultrasound may have up to 30% chance of having bowel endometriosis at the same time.

Deep transvaginal pelvic ultrasound in specialised centre may help discover tender endometriotic nodule(s) infiltrating into the rectal-sigmoid wall, co-existing ovarian endometriosis, bladder endometriosis or adhesions.

Colonoscopy, often advised to exclude inflammatory bowel diseases, may detect rectal -sigmoid stricture or rarely mucosal ulceration due to full-thickness endometriosis infultration into the bowel lumen. More often, however, colonoscopy is often negative resulting in false diagnosis of irritable bowel syndrome.

Laparoscopy remains the gold standard for assessment of endometriosis.

What treatments are available for bowel endometriosis?

The treatment options generally follow the same principles outlined in the CARE Endometriosis brochure. The options may include:

  • wait and see
  • fertility treatments 
  • medical treatments with progestogens or GnRH analogues
  • surgery for removal of endometriosis

Bowel endometriosis requires a team of specialists working together to thoroughly assess the risks and benefits of treatments and to determine the optimal care.

What does surgery for bowel endometriosis involve?

If pain and bowel symptoms are severe, and/ or where fertility is a major consideration, surgery for removal of the affected bowels may be advised. The extent of bowel surgery may range from shaving of the disease from the bowel wall, full-thickness removal of lesions which invade deep into the wall (disc excision), or segmental resection and reanastomosis where a large segment of the bowel is affected.

What are the risks of surgery for bowel endometriosis?

Surgery for removal of bowel endometriosis is one of the most challenging and difficult types of pelvic surgery as it is generally done for severe endometriosis involving the rectovaginal septum and / or recto-sigmoid. The aim is to safely and adequately remove the bowel endometriosis. In the majority of cases, this can be done by shaving or full-thickness disc excision without the need for segmental resection. However, where endometriosis has infiltrated deeply into the bowel wall resulting in bowel stricture or multiple deep lesions, rectal resection may be necessary / unavoidable. This  decision can only be made at the time of surgery.

The major risks of bowel surgery include:
  • Short-term – infection, leakage of bowel content during the postoperative healing phase, peritonitis, septicaemia, temporary bowel diversion (colostomy or ileostomy)
  • Long-term – bowel dysfunction (frequency, urgency, incontinence)

At CARE, we have gathered a Multi-disciplinary Endometriosis Research and Clinical Care (MERC) in order to optimise the care of women with complex, severe bowel and urinary tract endometriosis.

Our team includes A/Professor Alan Lam, Dr Jessica Lowe (gynaecologists), colorectal surgeons (Dr Justin Evans, Dr Yasser Salama, Dr Sharir Kabir, ), urologists ( Dr J Vass, G Coombs), and specialist nurses at North Shore Private, The Mater, Royal North Shore hospitals, anaesthetists (Dr Stephen Ford, Dr Andy Liew, Dr J McNamarra), pain specialists (Dr Glen Sheh).