Functional Investigation with Use of Anorectal Physiology in the Patients with Fecal Incontinence

Chung, Soon Sup; Park, Ung Chae; Kim, Bo Gyoon; Seong, Moo Kyung; Shin, Hyun Joon; Choi, Young Chil; Choi, Jin Yong

Abstract

BACKGROUND: A large amount of attention in anorectal physiologic studies has been devoted to the diagnosis of fecal incontinence. The current study was designed firstly to assess the physiologic characteristics of fecal incontinence and secondly to analyze how the physiologic findings correlate with each other.
METHODS
The physiologic findings of 47 patients (24 men and 23 women) were analyzed, retrospectively. Studies included anal manometry (n=38), anal electromyography/pudendal nerve terminal motor latency (PNTML) (n=30), and endoanal ultrasound (n=37). The degrees of continence were estimated by using continence grading scores (CGS) that ranged from 0 to 20 points based on the type and the frequency of incontinence. Control data were obtained from volunteers (n=23).
RESULTS
The patients were categorized as having neurogenic (group I, n=25) or myogenic (group II, n=17) incontinence. Despite intensive investigations, unknown etiology was noted in 5 patients (10.4%). The CGS was not different between groups I and II. Pudendal neuropathy was found in 96% of group I and 37.5% of group II patients. Group I showed a higher value of PNTML than that of group II (2.96 1.0 msec vs. 2.07 0.48 msec, p=0.003). The CGS was proportional to the value of the PNTML in group I (r=0.476, p=0.01). However, no correlation was found between the mean PNTML and the CGS in group II. In the manometric parameters, there were no statistical differences between the values of the mean resting pressure (RP), the maximum RP, and the maximum voluntary contraction (MVC) between groups I and II. The MVC was inversely proportional to the CGS in group I (r= 0.616, p=0.02) and in group II (r= 0.664, p=0.02). No correlation was found between the PNTML and the manometric parameters. When we consider the presence of a defect or a scar as an abnormal anal ultrasound finding, such findings were more frequent in group II than in group I (group I, 20% vs. group II, 88%, p<0.001, Fisher's exact test).
CONCLUSIONS
The value of the PNTML had relevance to the degree of symptoms in the patients with neurogenic incontinence. Specifically, the squeeze profiles of the manometric parameters were inversely related to the grade of incontinence. No correlation between the PNTML and the manometric parameters could be independently specified based on the etiology. Complementary examination by using the PNTML and anal ultrasound provided the only useful information to discriminate the etiology of incontinence.