A system to treat people who can't control their bowel movements (fecal incontinence) has been approved by the U.S. Food and Drug Administration.

Fecal incontinence is a common but underreported problem, especially among older adults the FDA said. A common cause is damage to the muscles around the anal sphincter from vaginal childbirth or diseases such as diabetes.

The Fenix Continence Restoration System was approved for use in patients who cannot receive, or have not responded to, surgery or other types of treatment, the FDA said.

The system includes a ring-shaped implant consisting of titatnium beads with magnetic cores that are connected by titanium wires. The magnetic attraction between the beads assists the anal sphincter in order to reduce the opening of the anal canal and the risk of severe fecal incontinence.

"Non-invasive treatment options for fecal incontinence, such as drugs, dietary changes and other medical measures, sometimes don't adequately address a patient's symptoms," Dr. William Maisel, acting director, Office of Device Evaluation, FDA Center for Devices and Radiological Health, said in an agency news release.

"The Fenix System affords a viable surgical option to address this condition when other methods have failed to improve a patient's quality of life," he added.