Endometriosis is a disease of the reproductive system, caused by the growth of endometrial cells outside the uterine cavity on the various surrounding pelvic organs. The symptoms of endometriosis consist essentially of chronic and/or cyclical pelvic pain such as menstrual pain (dysmenorrhoea), sexual pain (dyspareunia), urinary and digestive pain and bleeding from the uterus (menorrhagia), rectum (rectorrhagia) and bladder (haematuria). 40% of cases of endometriosis can be linked to infertility.