Constipation associated with chronic spinal cord injury: the effect of pelvic parasympathetic stimulation by the Brindley stimulator.

Ten subjects with severe constipation due to complete spinal cord injury (SCI) had prolonged oro-anal transit time (p less than 0.01), diminished faecal water content (p less than 0.05) and a reduced frequency of defaecation (p less than 0.01) compared to 10 non-SCI subjects. Paraplegics with an implanted Brindley S234 anterior sacral nerve root stimulator had a significant increase in frequency of defaecation (p less than 0.01), compared to the SCI group while the faecal water content was less although not significantly so. The Brindley stimulator group also showed a more rapid colonic transit than the SCI group but this did not reach statistical significance. SCI is associated with constipation which therefore appears to be favourably influenced by the Brindley S234 anterior nerve root stimulator. The effects produced are compatible with stimulation of left colonic motility, which facilitates the emptying of the distal colon, but also suggest that part of the response restricts transit in some areas of the colon or rectum. Since the motility changes induced by the Brindley stimulator do not affect the right colon a relatively greater residence time of the faecal bolus in this part of the large bowel would enhance water absorption.