B a c k g r o u n d: Assessment of the neurocontrol of the external anal sphincter has long been restricted to investigating patients by invasive tools. Less invasive techniques have been regarded less uitable for diagnosis. O b j e c t iv e: The aim was to develop a surface electromyography-based algorithm to facilitate fecal incontinence diagnosis, and to assess its sensitivity and specificity. D e s i g n: Data analysis from a single center prospective study. P a t i e n t s: All patients from colorectal surgery office were considered. They underwent a structured interview, a general physical and proctologic examination. Patients with diagnosed fecal incontinence (Fecal Incontinence Severity Index >10) were included into the study group. The control group consisted of healthy volunteers that scored 5 or less and had negative history and physical exam. Both groups underwent the same tests (rectoscopy, anorectal manometry, transanal ultrasonography, multichannel surface electromyography and assessment of anal reflexes). M e t h o d s: EMG results were analyzed to find parameters that would facilitate fecal incontinence diagnosis. O u t c o m e m e a s u r e s: Sensitivity and specificity of surface electromyography, to diagnose fecal incontinence, were assessed. R e s u l t s: A total of 49 patients were included in the study group (mean age ± SD 58.9 ± 13.8). The control group (n = 49) gender matched the study group (mean age ± SD 45.4 ± 15.1). The constructed classification tree, based on surface electromyography results, correctly classified 97% of cases. The sensitivity and specificity of this classification tree, to diagnose FI, was 96% and 98% respectively. L i m i t a t i o n s: The age of women in the control group differs significantly from mean age of other groups. C o n c l u s i o n s: Surface electromyography is an good tool to facilitate diagnosing of fecal incontinence.