He recommended doing a laparoscopy to find out what was going on. What a way to start married life. Generally endometriosis in the rectovaginal septum is more likely to deeply invade the underlying structures. Studies have shown that sisters have a six times increased risk compared to their husband's sisters. Other studies show up to an eight times increased risk when compared to other women.
Affected sisters are more likely to have severe disease than other.
Although these studies suggest a genetic basis, presently, the mode of inheritance is unknown. No one theory seems to explain all cases. An abnormality in the immune system allows normally shed endometrial cells to attach and grow. The disease is caused by a genetic birth defect as evidenced by the tendency for it to run in families. The endometrial tissue spreads from the uterus to the abdominal cavity through the lymphatic system or bloodstream.