Anorectal Function with High-Resolution Anorectal Manometry in Active Ulcerative Colitis and after Remission: A Pilot Study

Background: Ulcerative colitis may impair anorectal function, causing disabling symptoms such as incontinence and/or increase in the stool frequency, urgency and tenesmus. Data on anorectal function in these patients evaluated by conventional anorectal manometry are conflicting. Objectives: The aim of this prospective study was to assess by means of high resolution anorectal manometry the anorectal function in patients with mild-to-moderate ulcerative colitis at presentation and after remission. Anorectal function of ulcerative colitis patients was compared to that observed in healthy volunteers. Methods: 20 patients with mild to moderate left-sided ulcerative colitis or proctitis and 20 healthy volunteers were prospectively enrolled. All ulcerative colitis patients underwent high resolution anorectal manometry before treatment and after clinical remission. Results: Ulcerative colitis patients showed similar values for anal sphincter function as healthy volunteers, whereas rectal threshold volume for the first sensation, desire to defecate, urgency to defecate and maximum discomfort were significantly lower than in healthy volunteers (p<0.05). Rectal compliance was significantly lower in ulcerative colitis than in healthy volunteers (p<0.05). After remission, rectal threshold volumes, as well as rectal compliance, significantly increased. An inverse linear correlation was found between regression of urgency and stool frequency and rectal compliance (r=0.811; p<0.05). Conclusion: Ulcerative colitis patients show altered rectal function, with increased rectal sensitivity and lower compliance, compared to controls. This altered function is restored after successful treatment of the underlying inflammatory process. Finally high resolution anorectal manometry provides useful information on anorectal functionality and, in our opinion, should be preferred over conventional manometry.