A pus-filled lump near the anus is often an abscess. While warm povidone-iodine (Betadine) baths and prescribed antibiotics can help soothe the area and control infection, they often cannot completely cure it on their own because medicine has difficulty fully penetrating the pocket of pus. A simple, minor procedure to drain the fluid is usually the most effective way to provide immediate pain relief and ensure proper healing. Please consult a doctor or a general surgeon promptly so they can safely evaluate the lump and guide you on the most comfortable path to recovery.