Last updated: 11/24/2009

As a proven treatment for urinary incontinence, sacral nerve stimulation (SNS) has recently been found effective in the treatment of interstitial cystitis, a disorder that involves hyperreflexia of the urinary sphincter. SNS is also used to treat pelvic...

or urinary pain as well as fecal incontinence.

A person's ability to hold urine or feces depends on three body functions:

• a reservoir function represented by the urethra/bladder or colon
• a gatekeeping function represented by the urethral or anal sphincter
• the brain's ability to control urination, defecation, and nerve sensitivity

A dysfunction or deficiency in any of these components can result in incontinence. The most common forms of incontinence are stress urinary incontinence and urge incontinence. Stress incontinence is related to an unstable detrusor muscle that controls the urinary sphincter. When the detrusor muscle is weak, urine can leak out of the bladder from pressure on the abdomen caused by sneezing, coughing, and other movements. Urge incontinence is characterized by a sudden strong need to urinate and inability to hold urine until an appropriate time; it is also associated with hyperactivity of the urinary sphincter. Both conditions can be treated by SNS. SNS requires an implanted device that sends continuous stimulation to the sacral nerve that controls the urinary sphincter. This treatment has been used with over 1500 patients with a high rate of success. It was approved in Europe in 1994. The Food and Drug Administration (FDA) approved SNS for disturbances that are usually treated by augmentation of the sphincter muscle or implanting an artificial sphincter can benefit from electrical stimulation of the sacral nerve. Although the mechanism of SNS is not completely clear, researchers believe that the patient's control of the pelvic region is restored by the stimulation or activation of afferent fibers in the muscles of the pelvic floor.