PURPOSE: This study was undertaken to identify those factors from the history and examination which might predict the pathophysiologic basis of idiopathic fecal incontinence. METHODS: In a prospective study of 237 patients with idiopathic fecal incontinence (female to male, 7:1.7; mean age, 54.8 years; median history, 3 years), history, examination, and anorectal physiology studies findings have been analyzed using contingency table analysis. RESULTS: In patients with idiopathic fecal incontinence, anorectal physiology studies have shown that a low maximum basal pressure (<45 cm H2O) is predominantly attributable to internal anal sphincter weakness, and low maximum squeezing pressure (<76 cm H2O) is indicative of voluntary sphincter deficiency. In this study, a low maximum basal pressure is correlated with leakage, gaping of the anus on traction of the anal verge, and decreased resting tone on digital examination (allP< 0.05). A low maximum squeezing pressure is correlated with incontinence en route to the lavatory, urgency, both stress and urge incontinence of urine, reduced voluntary contraction in the external anal sphincter and puborectalis on digital examination, and a reduced or absent anorectal angle (allP<0.05). CONCLUSION: This study has shown that an informed history and digital examination can predict the manometric findings of specialist anorectal physiology studies. © 1994 American Society of Colon and Rectal Surgeons.