Anorectal physiology following spinal cord injury

Purpose: Spinal cord injured (SCI) patients have delayed colonic motility and anorectal dysfunction resulting in functional obstruction and constipation. This may be caused by changes in descending modulation from the central or sympathetic nervous systems. Anorectal dyssynergy may demonstrate similarities to that seen in the bladder following SCI. Methodology: Anorectal manometry was performed on 37 SCI volunteers. Patterns of rectal and sphincter function were identified. These patterns were then compared with questionnaire answers on bowel function and cystometrograms to identify a relationship between detrusor dyssynergy and anal sphincter tone. Results: Rectal compliance and basal resting sphincter pressures were lower than normal values. Ramp rectal inflation demonstrated patterns of sphincter activity similar to that recorded in the patients' cystometrograms. There is no definite relationship of bowel function to the findings on manometry in SCI patients. Conclusions: SCI patients have abnormal anorectal function. Anorectal manometry results were able to be classified into four patterns on the basis of rectal pressure and sphincter tone in response to rectal distention. The patterns of anorectal manometry seen were similar to those in cystometrograms, however there is no definite relationship to bowel dysfunction.