Endometriosis is a condition where cells of the endometrium are abnormally located outside the uterine cavity, commonly in the pelvis behind the uterus and ovaries. The endometrium is tissue that lines the inner surface of the uterus and respond to ovarian hormones. If pregnancy does not occur the lining is shed as a bleed which is commonly known as a ‘period’.

Endometriosis may be caused by backflow of menstrual blood through the fallopian tubes into the abdomen. During each period, this tissue outside the uterus bleeds in the same way as the lining of the uterus. Unlike normal uterine bleeding, the areas of endometriosis have no access to the outside and bleed into the pelvis. This leads to inflammation, pain and scar tissue. Endometrial tissue is commonly found in the ovary where it can form cysts, called chocolate cysts because of the brown colour and thick consistency of the trapped blood.

Endometriosis affecting various areas around the uterus.

Many women have symptoms, especially painful periods (dysmenorrhoea), lower abdominal and pelvic pain, deep pain during intercourse (dyspareunia) and heavy periods (menorrhagia). Trouble falling pregnant (infertility) is a common association with endometriosis.

Diagnosis is by a combination of history, clinical examination, pelvic ultrasound and laparoscopy. Management includes medical methods in the first instance, but often requires surgical procedures such as laparoscopic ablation by helica or diathermy, laparoscopic excision of endometriotic nodules, ovarian cystectomy, and in severe cases hysterectomy with removal of the ovaries.