A fistule is defined as a canal or a cavity, created by necrotic degradation of the tissue, which may, (but not necessarily has to) communicate directly with the digestive tract via an internal orifice. In čase of the Crohn's disease, the abscesi and fistules result from the samé pathological process and are caused by penetration of the inflammatory process through the wall of the digestive tube and to its outer side. The authors, having initially described the types and the pathogenesis of the anal fistules in the Crohn's disease, present a brief examination algorithm including examination of the whole digestive tract, based on the pan-entero-colitic character of the disorder. Sound diagnostics and establishment of the disease activity is very important, beacuse the treatment stratégy differs from ťhat of other perianal inflammatory affections. Furthermore, options for both the surgical and conservative treatment are listed in this work, including experience with use of the advancement flap. According to some authors, the success-rate of this treatment reaches up to 80%.

        Key words: anal fistule - Crohn's disease - digestive tract