[Some critical issues in the diagnosis and treatment of complex anal fistula]

In the past thirty years, colorectal surgeons have made great progress regarding the diagnosis and treatment of complex anal fistula, including the improvement of the accuracy of the preoperative evaluation of complex anal fistula, the improvement and standardization of the diagnosis and treatment of perianal fistulising Crohn's disease, the application of various "sphincter-sparing" procedures. However, complex anal fistula continues to prove a formidable challenge with a high recurrence rate and high incontinence rate. The variety of the surgical treatment also means that there is still no established "golden standard" with respect to that of the complex anal fistula. According to recent relevant literatures and personal experience, some critical issues in the diagnosis and treatment of complex anal fistula, including the approach to the accurate diagnosis, the value and significance of seton technique, the individual algorithm between the minimal invasive and extensive surgical treatments, the value of biopsy, are discussed in this article.