In recent years, with the rapid development of anorectal surgery technology and the popularization of the concept of painless and minimally invasive, the degree of post-operative pain for anal patients has been greatly reduced. Most patients feel only mild pain on the day after surgery, and after the second day after surgery, except for the temporary pain of changing medicine and defecation, they usually do not feel too much pain. However, there are individual differences in sensitivity to pain. For example, the elderly are not sensitive to pain due to the decline of various bodily functions. However, there are individuals who are very sensitive to pain due to a lower pain threshold. In the face of pain, many patients prefer to persevere and endure rather than accept painkillers. This idea of rejecting the use of painkillers is due to the fact that many people believe that: painkillers have no benefit other than pain relief. Although any drug has side effects, the side effects of painkillers are often magnified by the one-sided understanding of patients. Many people believe that the application of painkillers may produce side effects such as dependence, addiction and affecting wound healing. In fact, whether the drug is addictive or not is related to the nature of the drug itself and the duration of use. Generally applying certain painkillers in large quantities over a long period of time may result in drug addiction. Currently commonly used painkillers addiction is very low, and moreover, after anal surgery is generally a small dose of temporary medication, the possibility of addiction basically does not occur. Even when applied over a long period of time, the correct use of analgesics does not increase the probability of addiction, according to international research statistics. Similarly, if applied in large quantities over a long period of time, it is only likely to lead to delayed wound healing, which is not caused by temporary application in small doses in anorectal medicine. What are the complications and their causes due to pain in anorectics? 1, pain leading to urinary retention: the close connection of the perineal nerve relationship. Due to the effect of anesthetic drugs after anorectal surgery coupled with local pain and discomfort in the anus, can cause spasm of the urethral sphincter, resulting in urinary retention occurs, if necessary, must be catheterized. Catheterization is an invasive operation, not only soreness and discomfort, but also prone to urinary tract infections, so since the loss is not worth it. 2, the pain leads to fecal impaction: anal pain, leading to the patient’s fear of defecation. Patients often interrupt defecation due to pain, after the pain, the valuable intention to stool has disappeared without a trace. Repeatedly, a large amount of feces collects in the recto-pubic abdomen. The patient not only suffers from increased pain, but also from a sensation of falling that is worse than the pain, a sensation that is not helped by the use of painkillers. Pain – fecal impaction – anal fall – urinary retention, forming a vicious circle. This back-and-forth attack makes it difficult for people to sit or lie down. 3, pain leads to delayed healing: pain will lead to anal sphincter spasm. The anal sphincter belongs to the autonomic innervation, not your strong willpower, want to control the muscle can be controlled. Repeated and continuous spasm of the anal sphincter will lead to local wound drainage and blood microcirculation, insufficient blood supply. Wound ischemia and lack of oxygen, granulation edema pale and not bright red, resulting in delayed healing. 4, pain leads to immunity decline: pain also affects the body’s endocrine and immune function, easy to concur with the same whistle infection, which also affects the incision healing a reason. 5, pain leads to increase cardiovascular burden: post-surgical pain will stimulate the body’s sympathetic nervous system, making the blood pressure rise, heart rate accelerated, thus increasing the cardiac load, which is particularly unfavorable for patients with circulatory system diseases at the same time.