In clinical practice, it is generally best not to close the external opening of an anal fistula. Keeping the drainage unobstructed can prevent the infection from worsening or the formation of multiple branches. This is because when the fistula drains properly, the infectious secretions can flow out of the external opening. However, if the external opening does close, the infected tissues and secretions will accumulate within the fistula and then spread to the surrounding areas, forming branches and leading to an increase in the number of branches, thus creating a complex anal fistula and increasing the difficulty of future surgeries. Therefore, it is best not to close the external opening of an anal fistula. Clinically, the treatment for an anal fistula involves fistulectomy, which primarily involves removing the internal opening and the fistula. The external opening also needs to be treated. Postoperatively, medications such as erythromycin ointment gauze strips should be used for dressing changes.