Endometriosis is a serious and often frustrating diagnosis. One that can only be determined by surgical findings of endometrial cells outside the uterus. Women are often told after examination well "it's probably endometriosis."
https://www.sciencedirect.com/topics/medicine-and-dentistry/endometriosis
https://pubmed.ncbi.nlm.nih.gov/32031903/
https://www.who.int/news-room/fact-sheets/detail/endometriosis
https://www.sciencedirect.com/science/referenceworks/9780128122006