Endometriosis is a female disorder that involves the endometrium (the lining of the uterus). With this condition, endometrial tissue, which would normally grow inside the uterus, forms in other areas, outside the uterus itself. This can include tissue growth on the ovaries, fallopian tubes, bowel and pelvic-lining tissues. It is unusual for this tissue growth to spread beyond the pelvic region.
Endometriosis tends to be a common gynaecological disorder that affects many women, but is rarely dangerous. However, it can be painful and cause fertility issues.