An acute anal fissure of just 2 to 3 days is highly treatable and rarely requires surgery. Surgery is typically reserved for chronic cases that fail to heal after several weeks. The prescribed medications, amoxicillin/clavulanate and nitrofurantoin, are antibiotics; they do not directly heal a fissure but may have been prescribed if your doctor suspected an associated infection. Standard treatment for a fresh fissure focuses on stool softeners, a high-fiber diet, warm sitz baths, and soothing topical ointments. I highly recommend seeking a second opinion before considering surgery, as conservative, non-invasive treatments are usually very effective at this early stage.