Chronic pelvic pain that occurs because of pelvic venous disease (sometime referred to as pelvic congestion syndrome) is often felt below the belly button in the pelvis. A number of conditions can cause chronic pelvic pain, including enlarged varicose veins in the ovaries and pelvis. In the pelvis, veins have one-way valves that help keep blood flowing toward your heart. If the valves are weak or damaged, blood can pool in your veins, which causes them to swell. When this happens near the pelvis, it is called pelvic venous disease (PeVD). Women with pelvic venous disease often experience pain during or following intercourse.
Pelvic venous disease usually affects women who have previously been pregnant because the ovarian and pelvic veins widened to accommodate the increased blood flow from the uterus during pregnancy. After the pregnancy, some of these veins remain enlarged and fail to return to their previous size, causing them to weaken, allowing blood to pool.