This study was designed to detect factors that predict the occurrence of continence disorders after anal fistulotomy.A retrospective study of the charts of 312 patients was undertaken. A questionnaire was sent to all patients, with a response rate of 90 percent.Minor continence disorders occurred in 73 patients, incontinence did not occur. Multivariate analysis (chi-squared test) was performed showing that extensions (P = 0.008), location (P = 0.03), and level (P = 0.029) of the anal opening appeared to be independent factors.Patients with high openings, posterior openings, or fistula extensions are at risk to develop continence disorders after anal fistulotomy.