Mo2110 Assessment of Chymase Inhibition on Acute restraint Stress-Induced Visceral Hypersensitivity and Intestinal Dysfunction In Vivo.

Abstract

Objective Intact anorectal function is integral to the maintenance of faecal continence. Anal ‘sampling' describes the process by which intermittent relaxation of the anal canal allows detection of rectal contents. Previous studies report such events to be subliminal; however data capture was limited by obsolete technology necessitating retrospective analysis. With the advent of high-resolution anorectal manometry (HRAM), this study aimed to re-evaluate the phenomenon of transient anal sphincter relaxations (TASRs) in healthy volunteers. Methods Twenty-one healthy volunteers (16 F;median age 34, range 22-69) without anorectal dysfunction underwent HRAM using a solid-state catheter incorporating 11 channels, spaced at 8 mm intervals. The study was performed in the sitting position for 45 minutes preand post consumption of a standardizedmeal (828 kcal; 48 g fat). Participants reported perception of any gastrointestinal / anorectal sensations in real-time. TASRs were defined as an equalization of rectal and anal pressures involving ≥20% of the anal canal. Characterization of anorectal pressures changes, event duration and association with perception were recorded. Statistical analysis utilized Wilcoxon matched pairs and Mann Whitney U tests. Results TASRs occurred more frequently following meal consumption (median 3 [IQR 1-6] vs. 0 [0-1]; P=0.01). Median TASR duration was 23 seconds [19-27] and involved a 44% reduction in average anal canal pressure (65 mmHg [53-81] before vs. 36 [28-44] during; P=0.0001). TASRs were accompanied by a 45% increase in rectal pressure (18 mmHg [15-23] before vs. 25 [19-33] during; P=0.001). Fifty-six percent were temporally associated with gastrointestinal / anorectal sensations, most commonly the urge to pass wind (74% perceived events). Perceived TASRs involved a greater length of the anal canal (62% of total length with perceived vs. 53% not perceived; P=0.005). Conclusion To the authors' knowledge, this is the first prolonged study of anorectal function usingHRAM. TASRs are uncommon preprandially and occur more frequently following meal consumption. Contrary to previous reports, the majority of TASRs are perceived, associated with the urge to pass wind. Alteration of TASR characteristics and relation to sensory perception may be important in the pathophysiology of colorectal disorders (e.g. incontinence); such studies, including the effect of intervention are ongoing.