Electrical stimulation of the sacral dermatomes in spinal cord injury: effect on rectal manometry and bowel emptying

The impairment in defecation function that comes as a result of spinal cord injury may have a significant negative impact upon quality of life. Electrical stimulation (ES) of the somatic nervous system has been used to elicit autonomic reflexes in animals, before and after spinal cord transection. To determine whether ES might be used to promote bowel emptying, seven persons with recent spinal cord injury (SCI) and seven control subjects were studied. Electrical stimulation of the second sacral dermatome was applied during rectal manometry in both groups, and ES was added to the bowel programs of SCI patients. A significant rise in the number of rectal pressure spikes was noted in both groups after application of ES (p < .002, f = 6.34). There was no significant differences between the SCI and control groups when measuring the amplitude of spike waves in the colon. No significant change was noted in the time required for SCI patients to initiate a bowel movement, or in the time required to complete bowel emptying. Electrical stimulation of the sacral dermatomes can result in a change in the bowel activity of the recto-sigmoid colon. To date, no clinical effect on bowel emptying has been demonstrated.