[Consensus of Chinese experts on the diagnosis and treatment of anal fistula (2020)].

Anal fistula is one of the most common diseases in colorectal and anal surgery. Most of them are formed after the abscess of perianal space reptures. Due to the complexity and diversity of pathological changes, the clinical efficacy of some patients is not optimistic, and there may even be serious surgical complications, including delayed healing of anal fistula or varying degrees of fecal incontinence, which significantly affect the quality of life of patients and even lead to disability. The Working Committee of Clinical Guidelines of Anorectal Physicians Branch of Chinese Medical Association organized some domestic experts to discuss and prepare this expert consensus. It is suggested that comprehensive evaluation of anal fistula, including detailed medical history, physical examination and necessary auxiliary examination should be conducted before treatment. Auxiliary examinations include fistulography, ultrasound, CT or MRI. The purpose of the auxiliary examination is to accurately determine the position of the internal orifice of the anal fistula, the direction of the fistula and its relationship with the anal sphincter. Adenogenic anal fistula needs surgical treatment after diagnosis. The operation methods can be divided into two types: operations breaching sphincter and operations preserving sphincter function. The former includes anal fistulectomy, anal fistulotomy and seton placement; the latter includes ligation of intersphincteric fistula (LIFT), rectal mucosal muscle flap advancement repair, anal fistula laser closure, video-assisted anal fistula treatment, etc. It is suggested to select or combine the application according to the specific condition of patients. Bioabsorbable materials include anal fistula plug and fibrin glue. Due to the characteristics of retaining sphincter function and reusability, it is recommended to be used selectively by qualified and experienced doctors. Proper wound management after anal fistula surgery can reduce the pain of patients, promote healing and reduce the recurrence of anal fistula. Because there is a certain risk of recurrence and fecal incontinence after anal fistula surgery, for some patients with complex condition, repeated operations or impaired anal function, we must be careful when choosing reoperation, and weigh the benefits of patients and the risk of fecal incontinence.