Characterization of Anorectal Functions and Overall Colonic Transit in Female and Male Patients with Dyssynergic Defecation

Abstract

Purpose: In non-elderly healthy people, there are no significant differences between genders in anal sphincter resting pressure1 or colonic transit2. There is a paucity of information regarding males with dyssynergic defecation (DD). Gender differences have not previously been evaluated in patients with DD. Our purpose was to compare anal sphincter pressures, balloon expulsion weights, and overall colonic transit by gender in DD. Methods: Medical records of 407 patients with constipation in whom a diagnosis of DD was made, based on evaluation by a single gastroenterologist (MC) at a tertiary medical center, were reviewed. Data from a previously published cohort of 390 patients (1994 to 2011) was updated to include patients up to June 2012. DD was characterized by anorectal manometry (ARM), balloon expulsion test, and overall colonic transit using validated scintigraphy. Primary endpoints were maximum anal resting pressure (ARP), maximum anal squeeze pressure (ASP), added weight (BW) to allow balloon expulsion (data censored if patient unable to expel balloon despite addition of >470 g) and overall colonic transit (geometric center, GC) at 24h (GC24). Effects of gender on study endpoints were assessed by Mann-Whitney rank sum test. Our lab previously reported normal GC24 values in 209 controls3: median=2.3 (IQR 1.8, 2.9): males (n=72): 2.6 (2.1, 3.1); females (n=136): 2.1 (1.7, 2.6). Results: The DD patient cohort consisted of 66 males (M) and 341 females (F). Median (IQR) values of age and BMI were: 45.5y (30.0, 58.0) and 23.6 kg/m2 (21.5, 26.3) for M; 37.0y (26.0, 49.0) and 21.4 kg/m2 (19.1, 24.5) for F. Significant differences by gender were observed in ARP, ASP and GC24. GC24 was significantly slower in both genders compared to same gender controls. Data in table are median (IQR) values with corresponding n=size/group in DD patients. Conclusion: Patients with DD have slower overall colonic transit compared to gender matched controls. In DD patients, males have significantly higher resting and squeeze anal sphincter pressures, and females have slower overall colonic transit at 24 hours. These data suggest that interpretation of tests in patients with suspected DD should be based on data from same gender controls.Table: [1748]