Where is Endometriosis Found?
Endometrial tissue is most commonly found in the pelvic cavity, especially on the ovaries, the fallopian tubes, and the tissue lining the pelvis.

In rare cases, endometriosis has been found inside the bladder, bowel, intestines, colon, rectum, appendix, on the skin, even in the lung, spine, and brain.

During the menstual cycle, the lining of the uterus thickens, breaks down and sheds out via the vagina each month as your hormone levels rise and fall.

Endometrial tissue behaves similarly to the uterus lining: it thickens, breaks down and bleeds each month. However, because there's nowhere for the blood from this mislocated tissue to exit your body, it becomes trapped, and surrounding tissue can become irritated.