The tissue growth (implant) typically occurs in
the pelvic area, outside of the uterus, on the ovaries, bowel, rectum
, bladder, and the delicate lining of the pelvis. However, the implants can occur in other areas of the body, too.
Each month a woman's ovaries produce hormones that stimulate the cells of the uterine lining (endometrium) to multiply and prepare for a fertilized egg. The lining swells and gets thicker.