Comprehensive Evaluation of Fecal Incontinence: A Preliminary Report of Anatomical Neurophysiologic Study
Kasaya Tantiphlachiva MD1, Jirawat Pattana-arun MD1, Chucheep Sahakitrungrueng MD1, Arun Rojanasakul MD1
Affiliation : 1 Department of Surgery, Chulalongkorn University, Bangkok, Thailand
Background : Fecal incontinence [FI] can lead to impaired quality of life and the prevalence is under-reported. The etiology
is multifactorial. Careful clinical and neurophysiologic test is used to demonstrate the underlying problem. The objectives of
this study are to demonstrate the systematic assessment of the subjects with FI and to compare the investigation findings of
the FI group with healthy volunteers.
Materials and Methods : Forty-three subjects with FI and 46 healthy volunteers were evaluated by history taking, physical
examination, anorectal manometry, endoanal ultrasound and selective use of pudendal nerve terminal motor latency test
[PNTML]. The results were compared.
Results : By anorectal manometry, subjects with FI had significantly shorter high-pressure zone (1.7 vs. 2.3 cm), lower
resting anal sphincter pressure (35.2 vs. 64.3 mmHg), lower maximal squeeze pressure (95.7 vs. 203.5 mmHg) and sustained
squeeze pressure (74.3 vs. 121.3 mmHg) (p<0.001). Rectal hyposensitivity and hypersensitivity were found in 61% and
23% of the subjects, respectively. Rectoanal inhibitory reflex was absent in 7% and impaired in 23% of subjects. Cough reflex
was impaired in 21%. Saline continence test was abnormal in 77% of FI subjects. By endoanal ultrasound, anal sphincter
defect or scar was found in 86% of the FI subjects. Anal canal length was found to be significantly shorter in subjects with
FI both in the anterior (12.4 vs. 30.4 mm) and posterior (20.1 vs. 35.9 mm) position (p<0.001). In 10 FI subjects that
PNTML was performed, 6 subjects demonstrated either unilateral (3) or bilateral (3) pudendal neuropathy. Significant
correlation between FISI and posterior anal canal length was observed (r = 0.512, p = 0.015).
Conclusion : Various information of anorectal function and anatomy in subjects with FI can be obtained by systematic
approach. This information may be useful forthe management planning and patient education.
Keywords : Anorectal manometry, Endoanal ultrasound, Fecal incontinence, Neurophysiologic test, Pudendal nerve terminal motor latency test
