Appendicitis is known to be one of the most prevalent and frequent diseases in general surgery. Many people have experienced pain in the appendix area and need to take medications to relieve the pain in more severe cases, or even surgery in more severe cases. However, many patients with appendicitis report that they still feel pain in the right lower abdomen from time to time after appendectomy. This makes many patients wonder if the appendectomy has failed. In fact, there are various factors that cause pain after appendectomy: 1. The appendix itself The appendix is a tube-shaped organ located in the right lower abdomen behind the cecum, with one end being the blind end and the other end connected to the cecum. Blockage by fecal stone or parasite embedment, bacterial invasion and blood circulation disorder can cause septic inflammation of the appendix. When the appendix is surgically removed, the inflammation remains in the stump. If the stump is left too long, the dead cavity is created when the appendix is buried, which is equivalent to removing the appendix and leaving a “small appendix”, there is still inflammation to stimulate the peritoneum, which will produce abdominal pain, similar to the symptoms of chronic appendicitis attack or acute appendicitis. 2, the incision of the abdominal wall Appendiceal surgery must be incised abdominal wall layers, and then sutured layer by layer. Injury to the abdominal wall nerves during surgery due to incision, separation, suturing and postoperative scar compression can cause pain or numbness in the right lower abdomen. It can also be caused by the severance of sensory nerves at the abdominal wall incision site and the formation of tiny “neuromas” at the severed ends of the nerves. On examination, this pain can be found to be superficial, and sometimes small nodules can be found. Also, the silk sutures located on the skin surface of the abdominal wall are removed before discharge, but the silk sutures that close the subcutaneous tissue, muscle layer and peritoneum are not removed. The silk sutures left there as a foreign body can cause chronic irritation to the local tissues and some people may also feel pain. If the incision is contaminated or hematoma is formed by poor hemostasis during the operation incision infection occurs, not only pain but also redness, swelling and heat may appear and even abdominal wall abscess may be formed. 3. Periappendiceal tissue When the appendix is inflamed, the intestinal canal around the appendiceal mesentery and lymphatic tissue may also produce secondary inflammation. If the appendix is heavily diseased before surgery, with septicemia, gangrene, perforation, etc., or if medical treatment is late, the inflammation may spread to the tissues surrounding the appendix through the blood circulation and even form a residual abscess between the local intestinal canal and the greater omentum. In addition, adhesions between the intestinal canal and the intestinal canal, and between the intestinal canal and the greater omentum are often caused by tissue injury, bleeding, local tissue hemorrhage and necrosis, foreign bodies (e.g., talcum powder, threads) in the abdominal cavity, and intra-abdominal infection during surgery, which may produce pulling pain when the intestine moves. If the adhesions cause partial intestinal obstruction, in addition to pain, it may be accompanied by abdominal distension, nausea, vomiting, anal reduction of exhaustion or stopping exhaustion and other symptoms. 4. Diagnostic errors It is possible that other diseases similar to appendicitis were misdiagnosed as appendicitis before surgery and appendectomy was performed, while the primary disease was not treated, therefore, the symptoms were not reduced and there was still pain in the right lower abdomen. Diseases that are more likely to be misdiagnosed and still have abdominal pain after surgery include acute and chronic mesenteric lymphadenitis, right acute ureteritis, right ureteral calculus, right iliac fossa lymphadenitis, limited ileitis, ileocecal tuberculosis, and tumors. In addition to the above factors that may cause pain, there may be many other factors to cause postoperative pain. Only when the real cause of postoperative resection pain is known, it is possible to prescribe the right medicine to cure the disease. If the pain persists and cannot be relieved after appendicitis removal, you can come to the pain clinic for specialized treatment to completely cure your post-operative appendicitis pain through acupuncture and heat therapy, herbal hot compresses and other methods.