ANORECTAL FUNCTION AFTER RESTORATIVE PROCTOCOLECTOMY AND LOW ANTERIORRESECTION WITH COLOANAL ANASTOMOSIS

Anorectal manometry and electromyography were studied in 17 patients b efore and after restorative proctocolectomy with stapled pouch-anal an astomosis, in ten patients before and after low anterior resection wit h stapled coloanal anastomosis, and in 35 normal controls. More than 8 0 per cent of patients in both groups developed abnormal oscillation o f anal pressure after operation (amplitude 15-60 (median 25)cmH(2)O, f requency 4-10 (median 8) per min) and showed no anal relaxation in res ponse to intermittent neorectal distension. All patients lost discrimi native rectal sensation and none could perceive a normal desire to def aecate. Patients with postoperative soiling had a greater amplitude of anal pressure oscillation and lower minimum basal pressure, although those who underwent coloanal anastomosis had a greater risk of inconti nence because of large asynchronous oscillations in neorectal pressure . The common pathophysiological features after restorative proctocolec tomy and coloanal anastomosis probably relate to damage to the autonom ic and enteric nerve supplies. The presence of an unstable internal an al sphincter may be an important cause of postoperative nocturnal inco ntinence.