If your girlfriend is diagnosed with endometriosis, she might want to look into changing her diet to a whole food plant based / vegan diet and supplementing with iodine.
Here are the links to 2 youtube videos, which are lectures by:
Dr. Neal D. Barnard, M.D., F.A.C.C.. At 16:25 he talks about the case of a woman, suffering from endometriosis, which she cured by changing her diet.
Dr. Jorge Flechas, M.D.. At 4:39 he talks about the fact, that iodine deficiency can cause endometriosis.
I have been suffering myself from extremely heavy periods, (I am talking Niagara Falls type of