Vaginal inserts designed to treat a condition called pelvic organ prolapse may have high rates of complications in the long term, a new study suggests.

Pelvic organ prolapse is a disorder in which weakened muscles and supporting tissue in the pelvis allow one or more organs, including the uterus, bladder or rectum, to move from their normal positions and protrude into the vagina.

Some symptoms include pressure in the vagina and chronic pain in the lower abdomen or lower back.

More-severe cases may require surgery, but conservative treatments can also work. For women who are overweight, weight loss might help, while some women find symptom relief from exercises that strengthen the pelvic-floor muscles.

Removable devices called pessaries, which are inserted into the vagina to support the pelvic organs, are another treatment option. Versions of the devices have been used since the 15th century B.C., yet little has been known about their side effects when used for a prolonged period, according to the researchers on the new study.

Following 167 women who used a vaginal pessary for anywhere from a few months to 14 years, the investigators found that more than half — 56 percent — suffered a side effect. The most common ones included vaginal bleeding, severe discharge, pain and constipation.

In the end, most women stopped using the device, the researchers report in the obstetrics journal BJOG.

They say the findings suggest that for many women, pessaries are best used for a limited time.

"The vaginal ring pessary is still a useful treatment option," said researcher Dr. Kate H. Moore, of the University of New South Wales in Sydney, Australia.

"But after these results," she told Reuters Health in an email, "we tell our middle-aged patients that it is a short-term solution, for about two to five years."

Moore added that they still offer vaginal pessaries as a long-range solution to very elderly women, who are less likely to develop long-term complications.

The study included 167 women with prolapse who were fitted for a vaginal pessary over 10 years. Only 14 percent of the women were still using the device at the study's end. Women who discontinued the treatment used the devices for about two years, on average.

The patients gave a variety of reasons for stopping. Twenty-seven percent said they were unhappy with the pessary's side effects and, in most cases, chose to try exercise therapy.

Another 30 percent opted to have surgery — in some cases because they were unhappy with the pessary's effectiveness or side effects, or because of its inconvenience.

Surgical techniques for pelvic organ prolapse vary depending on which organs are involved, but in some cases, the uterus is removed. Surgery also carries its own potential long-term risks, including incontinence and pain during sex.

Moore said she is not aware of any studies that have compared the long- term effectiveness and complication rates of surgery with those of pessaries.