BACKGROUND: The current literature does not provide unequivocal data on prognostic factors in conservative management of fecal incontinence. Moreover, the physiopathologic effects of pelvic floor rehabilitation on anorectal function are not well understood. Our aim is to identify some prognostic parameters and assess their effects on anorectal physiology of biofeedback therapy plus anal electrostimulation for fecal incontinence. METHODS: We studied prospectively 45 consecutive adult patients with fecal incontinence treated at our institution with biofeedback plus electrostimulation. The outcome parameter was modification of the Wexner Incontinence Score (WIS) at the end of treatment. In addition, we studied the modifications of anorectal manometry and the rectal sensitivity threshold after treatment. RESULTS: At univariate analysis, age, the pretreatment WIS, and the pretreatment resting and maximum squeeze pressures were correlated with the clinical outcome. Patients showed a significant reduction in the rectal sensitivity threshold but no significant change in manometric parameters after treatment. CONCLUSIONS: We identify good sphincter function and mild to moderate symptomatology as favorable prognostic factors in biofeedback and anal electrostimulation therapy. Improvement in rectal sensitivity can be implicated in symptomatic improvement. The impossibility of correlating the clinical results with the effects on anorectal physiology suggests a nonspecific effect of conservative treatment.