Anal fistula is one of the common diseases in proctology. The formation of an anal fistula is caused by infection of the anal sinuses and anal glands. Due to damage to the anal sinuses and anal glands, bacteria from the intestines enter these areas. As immunity weakens, the bacteria cause localized inflammation, which then leads to the formation of an abscess. After the abscess bursts, an anal fistula forms. This is the pathogenesis of anal fistula.