Type of stress incontinence attributable to (ISD) sphincter muscle incompetence. It is also known as poor or nonfuctioning urethral closure mechanism, or Type III stress incontinence.

failure of the sphincteric mechanisms of the urethra to generate adequate pressure to retain urine in the bladder.

A cause of stress urinary incontinence in which the urethral sphincter is unable to contract and generate sufficient resistance in the bladder, especially during activities that increase pressure on the bladder (e.g. coughing, laughing). ISD may be due to congenital sphincter weakness, such as myelomeningocele or epispadias, or it may be acquired from prostate cancer treatments, trauma, radiation therapy, or spinal cord injury.