PURPOSE: Endometriosis is an inflammatory disorder in which the tissue that lines the inside of the uterus (the endometrium) spreads to the pelvic and peritoneal cavities outside of the uterus. This is a biological sample collection study examining how bacteria located within the vagina, the urogenital tract and the gastrointestinal tract may affect the development of endometriosis. Investigators are also exploring how an individual’s microbiome affects their estrogen metabolism and inflammation.