Endometriosis impacts approximately 200 million women worldwide, with an estimated 10 to 20 percent of women of childbearing age in the United States currently living with the disease. Endometriosis occurs when cells that should be in the lining of the uterus find themselves in other parts of the body such as the ovaries, uterus, bladder or other areas. This causes build up that sheds each month. That process repeats itself several times, which causes pain to the pelvic area.