Abstract Background The treatment of chronic anal fissure has shifted in recent years from surgical to medical. Methods A Medline search of studies relevant to modern management of chronic anal fissure was undertaken. Results Traditional surgery that permanently weakens the internal sphincter is associated with a risk of incontinence. Medical therapies temporarily relax the internal sphincter and pose no such danger, but their limited efficacy has led to displacement rather than replacement of traditional surgery. Emerging medical therapies promise continued improvement and new sphincter-sparing surgery may render traditional surgery redundant. Conclusion First-line use of medical therapy cures most chronic anal fissures cheaply and conveniently. The few non-responders can be targeted for sphincter assessment before traditional surgery. If the initial good results of new sphincter-sparing surgery are confirmed, it may be possible to avoid any risk of incontinence, while achieving high rates of fissure healing.