Bleeding next to the anus is commonly an infectious disease. Patients with perianal abscesses who have local rupture or have fistula formation, forming a visible fistula. It will manifest as local bleeding or purulent blood discharge, as well as recurrent low-grade fever and perianal pain, and defecation will lead to aggravation of symptoms, which also requires systematic treatment. For infectious diseases, the infection should be actively controlled, and surgical treatment should be performed to incise and remove the fistula, and for high anal fistulas, wire therapy is required. Regular postoperative drug changes are required, along with anti-infective therapy. Patients with atopic infections, such as tuberculosis or Crohn’s disease, are also prone to perianal fistula formation and should also be actively treated for underlying diseases after surgical treatment. Proper supplementation with vitamin-rich foods and regular colonoscopy are also needed.