Anal sphincter function was assessed by digital examination and anal canal manometry in 66 patients and controls. Digital scores were allotted by using visual analogue scales for basal and squeeze sphincter function and were compared with the corresponding pressures. There were good correlations between digital basal score and maximum basal pressure (Spearman rank correlation coefficient rs = 0.56, P less than 0.001), and digital squeeze score and maximum squeeze pressure (rs = 0.72, P less than 0.001). There were wide ranges of sphincter function on digital and manometric assessment with considerable overlap between patient groups. Digital scores detected differences in sphincter function between patient groups as accurately as manometry. The sensitivities and specificities of digital scores and anal canal manometry in segregating continent and incontinent patients were similar. It was concluded that digital estimation was equally as good as assessment of anal sphincter function as anal canal manometry.

Fourteen patients with ulcerative colitis underwent formation of an S ileal pouch and construction of a stapled pouch-anal anastomosis by a modified technique, which eliminated the use of purse-string sutures. Eleven have had their covering ileostomies closed. Anal manometry performed before and a median of 9 months after ileostomy closure showed significant impairment of internal anal sphincter function. Night evacuation was significantly reduced in the stapled group compared with a similar group of patients who had undergone S ileal pouch formation, mucosal proctectomy and manual transanal anastomosis, but this was the only parameter of function to show a difference. A stapled pouch-anal anastomosis may be superior to the conventional procedure but it still may lead to internal anal sphincter damage which cannot be due to mucosectomy or prolonged anal retraction.