Anal canal pressure and motility after ileoanal anastomosis.

This study was done to determine the effect of mucosal rectectomy and ileal pouch to anal anastomosis (IAA) on pressure and motility of the anal canal. Fifty patients, 22 +/- 2 months after operation (mean plus or minus standard error of the mean), and 30 healthy control volunteers were studied. Twenty-eight patients had excellent continence, while 22 had episodic minor incontinence. The maximum resting pressure in the anal canal was reduced in patients with episodic incontinence compared with continent patients and control volunteers. The increase in pressure with squeeze was slightly greater in continent than in incontinent patients. The frequency of the anal slow waves was less after IAA than in control volunteers and the amplitude of the waves was greater. The frequency and amplitude, however, were not related to continence or resting pressure. In conclusion, decreased anal canal resting and squeeze pressures after ileal pouch to anal anastomosis are associated with episodic minor incontinence, while altered motility patterns in the anal canal are not.