Pelvic pain may also occur at other times of the month or during sexual intercourse. Endometriosis is a condition in which tissue that looks and acts like the inner lining of the uterus is found outside of the uterus in the lower abdomen. It may be attached to the ovaries, the intestines, or some other part of the lower abdomen. This tissue is affected by female hormones as if it were in the uterus. At the end of each month this tissue bleeds, but since the fluid cannot be flushed freely out of the body, it builds up inside.
Nearby tissues become red, swollen, and painful.
The pain of endometriosis usually worsens over the years. PID is usually caused by sexually transmitted diseases . It causes menstrual pain that usually lasts longer than menstrual bleeding. The pain may begin early or late in the period and usually lasts for several days. Fibroids are tumors of the uterine wall.