The high recurrent rate and insufficient protection of anal function in treatment of anal fistula were reviewed in this article. To solve the problems in the treatment of complex fistula-in-ano including ignorance of preoperative assessment and lack of consciousness of preserving anal function, the authors raised the countermeasures to carry out the “gold standard” of preoperative assessment and the system of medical delivery, form the new principle of incision of anal sphincters, collect the high-level evidence-based medicine proof, improve the healing rate and significantly reduce the postoperative continence disturbance, so as to develop a new guideline for the treatment of fistula-in-ano.

Key words: Anal fistula, Surgical procedures, Operative, Problem solving, Decision making