Symptom Finder - Fecal Incotinence
INCONTINENCE, FECAL
Anatomy will serve us well in recalling the various causes of fecal incontinence. The pathway of voluntary control of this function begins in the cerebrum and travels through the brain stem, spinal cord, and nerve roots, to the “end organ,” which is the rectal sphincter.
Cerebrum: This should help recall the incontinence of Alzheimer disease, normal pressure hydrocephalus, and other causes of organic brain syndrome. It will also prompt the recall of the incontinence in functional psychosis and epilepsy.
Brainstem and spinal cord: This would bring to mind trauma, multiple sclerosis, transverse myelitis, syringomyelia, and brainstem and spinal cord tumors in which there is loss of voluntary control due to pyramidal tract damage.
Nerve roots: This should prompt the recall of cauda equina tumors, tabes dorsales, and spinal stenosis.
Rectal sphincter: Primary rectal sphincter incompetence leads to the release of small amounts of stool associated with anal fissures, hemorrhoids, and postoperative incontinence following a fistulectomy or episiotomy.
Approach to the Diagnosis
Before beginning an expensive diagnostic workup, pay attention to the history and physical examination. Is there a small volume of stool? Look for an anal fissure, hemorrhoids, or other causes of sphincter incompetence. If the incontinence is sporadic, look for organic brain syndrome, epilepsy, or functional psychosis. If the neurologic examination reveals pathologic or hyperactive reflexes in the lower extremities, consider a spinal cord or brain stem lesion. If there are hypoactive reflexes in the lower extremities, consider the possibility of cauda equina tumor or tabes dorsalis. Careful digital examination will often reveal a local cause. If the sphincter is tight, consider a spinal cord lesion. If it is flaccid, consider a lesion of the cauda equina or nerve roots.
Patients with signs of mental deterioration need a CT scan or MRI of the brain. Normal pressure hydrocephalus can be excluded by radioactive cisternography. Patients with hyperactive reflexes in the lower extremities need a CT scan or MRI of the suspected level of spinal cord involvement, whereas patients with hypoactive reflexes require an MRI of the lumbar spine or myelography. Anorectal manometry and defecography will assist in the diagnosis of anal and rectal sphincter dysfunction. A neurologist or
gastroenterologist may need to be consulted.
Anatomy will serve us well in recalling the various causes of fecal incontinence. The pathway of voluntary control of this function begins in the cerebrum and travels through the brain stem, spinal cord, and nerve roots, to the “end organ,” which is the rectal sphincter.
Cerebrum: This should help recall the incontinence of Alzheimer disease, normal pressure hydrocephalus, and other causes of organic brain syndrome. It will also prompt the recall of the incontinence in functional psychosis and epilepsy.
Brainstem and spinal cord: This would bring to mind trauma, multiple sclerosis, transverse myelitis, syringomyelia, and brainstem and spinal cord tumors in which there is loss of voluntary control due to pyramidal tract damage.
Nerve roots: This should prompt the recall of cauda equina tumors, tabes dorsales, and spinal stenosis.
Rectal sphincter: Primary rectal sphincter incompetence leads to the release of small amounts of stool associated with anal fissures, hemorrhoids, and postoperative incontinence following a fistulectomy or episiotomy.
Approach to the Diagnosis
Before beginning an expensive diagnostic workup, pay attention to the history and physical examination. Is there a small volume of stool? Look for an anal fissure, hemorrhoids, or other causes of sphincter incompetence. If the incontinence is sporadic, look for organic brain syndrome, epilepsy, or functional psychosis. If the neurologic examination reveals pathologic or hyperactive reflexes in the lower extremities, consider a spinal cord or brain stem lesion. If there are hypoactive reflexes in the lower extremities, consider the possibility of cauda equina tumor or tabes dorsalis. Careful digital examination will often reveal a local cause. If the sphincter is tight, consider a spinal cord lesion. If it is flaccid, consider a lesion of the cauda equina or nerve roots.
Patients with signs of mental deterioration need a CT scan or MRI of the brain. Normal pressure hydrocephalus can be excluded by radioactive cisternography. Patients with hyperactive reflexes in the lower extremities need a CT scan or MRI of the suspected level of spinal cord involvement, whereas patients with hypoactive reflexes require an MRI of the lumbar spine or myelography. Anorectal manometry and defecography will assist in the diagnosis of anal and rectal sphincter dysfunction. A neurologist or
gastroenterologist may need to be consulted.
