Patient Information > Gynaecological > Endometriosis

Endometriosis is a condition in which small pieces of endometrium (that is, the lining of the uterus) are found in locations outside the uterus.

Several symptoms are associated with endometriosis. Dysmenorrhoea (painful periods) is a common symptom. Pain may also be present during ovulation. The site or location and the nature of the endometrial implants, growths or nodules are important in relation to the pain. Nodules in the Pouch of Douglas, uterosacral ligaments or rectovaginal septum may cause excrutiating pain. They may be overlooked. Bowel and bladder symptoms are not well recognized. They may be diagnosed as irritable bowel syndrome (IBS) or bladder pain syndrome (BPS/IC). Bowel symptoms include abdominal pain and spasms ,painful bowel movements, constipation, nausea and vomiting. Bladder symptoms include pain in the bladder region, frequent urination and burning when urinating. The range and severity of symptoms often increase as the disease progresses, and the number of days in the month that the symptoms last often increases as the condition worsens. However the symptoms do not progress in all patients.

Some women experience pelvic pain which may be caused by tension on endometrial implants and nodules, pressure from an endometrioma (endometrial or chocolate cyst) or adhesions pulling on organs. Pain can be provoked by certain positions such as sitting and certain movements or activities. Adhesions may be a consequence of endometriosis and the symptoms do not change with the menstrual cycle. The type and location of adhesions varies and the pain can range from mild to incapacitating.

Endometriosis may be suspected with some of the following symptoms:

• dysmenorrhoea (painful periods)
• pelvic pain (which may not be during a period)
• dyspareunia (painful intercourse/sex)
• lower back pain
• ovulation pain
• bowel symptoms
• heavy bleeding

Endometriosis may especially be suspected if the symptoms are:

• not helped by taking painkillers such as paracetamol
• not helped by taking non-steroidal anti-inflammatory drugs such as mefanamic acid
• not helped by taking the oral contraceptive pill
• so painful that you struggle to carry out your normal activities
• occurring at the same time every month
• getting worse with time

GP's do not always think of endometriosis as a diagnosis until other possible diagnoses have been ruled out. If you suspect you may have endometriosis, it may be necessary to suggest this to your GP. It may also be necessary to ask about it more than once and you can ask to be referred to a gynaecologist. Endometriosis is diagnosed by laparoscopy (via a small incision in the abdomen) Some gynecologists have more knowledge and experience of endometriosis than others. You may want to find out about the situation regarding referral in your area.

If you are considering having a laparoscopy we have a list of questions you may want to ask about beforehand. This is available on request via the contact us page of the website.

Reviewed by Pr M Canis, Clermont-ferrand, France

                                Deeply Infiltrating Endometriosis

This severe form of endometriosis is found between the rectum and the vagina (known as recto-vaginal endometriosis), in the Pouch of Douglas, the uterosacral ligaments, the bowel, appendix, ureter, bladder, uterovesical fold or the pelvic wall. This type of disease may be found when endometriomas (an ovarian cyst filled with old blood, sometimes called a chocolate cyst ) are present.

It is known that very deep endometriotic nodules (more than 10mm ) are linked with severe pelvic pain and that it is an active disease. Analysis of the tissue shows that it is different from disease that is less than 1mm (superficial ) or 2 to 4 mm (intermediate ). Rupture of microcysts and leakage of a chocolate –like substance from these cysts proved the presence of deeply penetrating endometriosis. Deep biopsies contain nerve fibres and inflammatory cells within and around the implants. These findings may explain why deep implants cause pain. The depth of disease cannot be seen by looking. Surgically removing the disease and analysis is required to make an accurate assessment. Due to the location and the proximity to nerves and blood vessels, this type of surgery is highly specialized.   

Pelvic pain reported to be in the same location for a minimum of 6 months is usually linked with organic pathology. Pelvic pain that persists for this length of time is frequently associated with advanced stages of endometriosis. The pain can be intermittent or continuous. Localized tenderness on pelvic examination is linked with pathology in 97% of patients and endometriosis in 66%.The majority of the latter lesions were fibrotic (surrounded by fibrosis )  Painful periods (Dysmenorrhea) is the most common reported symptom with 51%-91% of patients with endometriosis reporting this. Pain may be caused by a build up of pressure in fibrotic lesions during menstruation. There is also a link between the advanced stages of endometriosis and pain deep in the pelvis during sexual intercourse (Dyspareunia ). This pain may be related to position and may be eased by changing position.   

Adhesion formation is common in patients with endometriosis and may be related to the degree of pain. Adhesions may cause pain by direct nerve damage from scar formation or as a result of damage to the pelvic organs due to loss of blood supply (ischaemia ). There may be adhesions of the bowel, ovaries, uterus etc causing any movement to place traction on their nerve supply. Over time, scarring at the back of the uterus may produce a fixed and retroflexed position. This can lead to referred  pain to the back, lower abdomen, rectum and thighs.

The American Fertility Society classification was designed to estimate fertility prognosis, not pain severity or response to treatment. There are pain scales that have been validated for acute or chronic pain but there are no pain scales that have been validated for pain of pelvic origin. There is a need for an accurate and precise method of quantifying pelvic pain. To create such a scale, anatomic disease must be correlated with the pain intensity and the degree of pain relief with treatment. This needs to be evaluated over time due to the recurrence rate once  treatment is discontinued.   

References :

Cornille F, et al Deeply infiltrating pelvic endometriosis: histology and clinical significance. Fertil Steril  1991

Fedele L, et al Pain symptoms associated with endometriosis. Obstet Gynecol 1992   

 Galle P, Clinical presentation and diagnosis of endometriosis. Obstet Gynecol Clin North Am 1989

Jensen J et al,The measurement of clinical pain intensity: a comparison of six methods. Pain 1986     

Images and photographs of some types of endometriosis including deep disease courtesy of Pr U. Ulrich, Berlin. The images take a couple of minutes to download.

For further information about endometriosis see Pelvic Pain Support - Clinician Information

For recent research into the discovery of nerve fibres in the endometrium in women with endometriosis, mechanisms causing pain in endometriosis and a possible less invasive way of

diagnosing or excluding endometriosis see Pelvic Pain - Research under the heading "Endometriosis"

The following powerpoint presentation explains how pain in endometriosis is caused and suggests some possible ways of dealing with it. There are notes accompanying the slides that can be read by saving the presentation on your computer.

PAIN IN ENDOMETRIOSIS- M Platt

For patient experience of endometriosis, treatments and self-help strategies etc , see message board:

http://www.pelvicpain.org.uk/forum/index.php