Good endo explanation

"Endometriotic implants cause a local inflammatory reaction which irritates nerve endings and sends noxious stimuli along the nerve pathways to the spinal cord and into the central nervous system (CNS) where they are interpreted as burning, dull, achy sensations or as sharp, stabbing, or crampy pains. The local inflammatory reaction is mediated by the increased production of substances, such as a variety of cytokines and prostaglandins, originating from the endometriotic implants and cells of the immune system. These substances also stimulate development of scarring and nodules around the endometriotic implants which may compress peripheral nerves compounding pain symptoms with signs of peripheral neuropathy. Pain symptoms are usually elicited when the nodules are compressed during pelvic examination or sexual intercourse. Endometriotic (chocolate) cysts may compress on other pelvic organs, causing pain and pressure during urination or bowel movements. If there is bleeding from the endometriotic lesions, as it frequently happens during the menstrual period, a woman may notice blood in the urine or stools or in secretions from other organs affected by endometriosis, e.g. blood in the sputum with endometriosis of the lungs. Because of increased systemic cytokine and prostaglandin production by the circulating immune cells, some women with endometriosis may experience generalized symptoms such as low-grade fever; crampy, generalized aches and pains; and nausea, vomiting, and diarrhea usually around the time of the menstrual period." http://www.endometriosisinstitute.com/endometriosis/management-of-pelvic-pain