the first phase is to correctly identify the fistula main tract and the fistula internal opening, not forgetting any secondary tracts or abscess cavities, very common condition in complex cases. During the operative phase, all fistula tracts and any possible abscess cavities are destroyed with a monopolar electrode passing through the operative channel of the fistuloscope, always visually. The necrotic material is removed with an endo-brush, here too, under direct vision. This technique has many advantages compared to the other techniques: treating the fistula under vision and from the inside, the risk to damage the sphincter appa­ratus is nil, no significant wounds are made on the perianal area, the patient doesn’t need painful dressings, and can manage his postoperative period at home. And more, the patient returns to work after a few days. However, the closure of the internal opening remains a weakness. This cannot be done with the fistuloscope. So, in this chapter, I’m showing at least four surgical methods to do it.