Patients experience pain after anal fissure surgery. Pain can be caused after any surgery on the anus, including fissure surgery, mixed hemorrhoid surgery, anal fistula surgery, etc. Because the nerves around the anus are very rich, a local fissure or trauma can cause severe pain around the anus. When the patient defecates, the local pain is aggravated because the stool passes through the anus. Wounds at the anus are usually open and unstitched after surgery, and may be combined with some bacterial infections, which can cause pain at the wound. Patients are advised to take oral analgesics to reduce local pain after surgery. If the pain is still more pronounced, intramuscular analgesic injection can be considered to relieve the pain.