The U.S. Food and Drug Administration recently highlighted the problem in a new advisory about vaginal surgeries that use mesh to repair pelvic organ prolapse, warning that the procedures are no more effective than other options while complications are common. As many as half of all women experience some type of pelvic prolapse -- a condition in which the bladder or other organs begin slipping out of place -- after childbirth, menopause or a hysterectomy, or with age. Symptoms are mild most of the time but can entail significant pain or discomfort. Yet scientific studies are scarce and little is known about which prolapse treatments are most effective for which patients. Of special concern are procedures that involve inserting mesh through the vagina to help hold up a woman's sagging bladder, bowel, uterus, intestines or rectum. Some experts are concerned that physicians are performing these surgeries without sufficient training. Others worry that patients without serious symptoms may be getting the procedures unnecessarily. Meanwhile, the FDA hasn't required companies selling mesh products to prove they're safe or effective when used in the pelvis, even though the potential harm can be substantial.