1, Chronic anal pain (1) Anal retentive muscle syndrome Etiology and pathogenesis[7] Often the cause is congenital, but also related to physical causes of injury, including trauma, excessive physical activity, and old age. It may also be the result of spasm of the pelvic muscles or over-contraction of the anorectal muscles in order to overcome one’s incontinence symptoms. Some studies suggest an association with stress, tension and anxiety, as well as with postoperative complications, including transabdominal rectal resection, anal fistula, and medial anal fissure incision. (2) Non-specific functional anorectal pain The etiology and pathogenesis are unknown, and psychological factors have a close relationship. Spasmodic anorectal pain The etiology is not clear, because of the short duration of the attack, the number of times, to the study has brought difficulties. Some studies suggest that smooth muscle spasm may be the cause of spasmodic rectal pain. Psychological tests showed that 63% of the patients had supremacism, 73% had anxiety, and 40% had hypochondriac tendency; in addition, 62% of the patients had multiple somatic symptoms. This suggests that psychosomatic factors may play a role in the development of this disease. 2, diagnosis and differential diagnosis (1) chronic anorectal pain diagnosis of chronic anorectal pain in the Rome III diagnostic criteria, according to the backward pull the puborectalis muscle with or without pressure pain, chronic anorectal pain is divided into two subtypes chronic anorectal pain: (1) chronic or recurring anorectal pain (2) the pain lasts for at least 20 min (3) to exclude other causes of anorectal pain: ischemia, inflammatory bowel disease, cryptitis, myositis, myocarditis, myopathy, myopathy, myococcusitis, myopathy, myococcusitis, myocardial infarctions, myocarditis and other causes. Bowel disease, cryptitis, intermuscular abscess, anal fissure, hemorrhoids, prostatitis, and coccygeal pain (the above symptoms appeared at least 6 months prior to the diagnosis and lasted for at least 3 months) Subtypes ① anorectal raphe syndrome: meets the diagnostic criteria for chronic anorectal pain and causes tenderness when the puborectalis muscle is pulled from the posterior ② nonspecific functional anorectal pain: meets the diagnostic criteria for chronic anorectal pain, and does not cause pain when the puborectalis muscle is pulled from the posterior. cause pain . Spasmodic anorectal pain: (1) recurrent episodes of pain located in the anal area and lower rectum (2) episodes lasting seconds to minutes (3) absence of anorectal pain in the intervals between episodes (diagnosis of PF symptom duration must be at least 3 months; for clinical diagnosis and evaluation, PF symptom duration can be less than 3 months) Anal retentive syndrome Anal retentive syndrome (LAS) is also referred to as retentive spasm, puborectal muscle syndrome, chronic anorectal pain. rectus syndrome, chronic rectal pain, pyriformis syndrome, and tension pelvic myalgia. In addition to meeting the Rome III diagnostic criteria for chronic anorectal pain (see Table 1), the pain is usually vague and dull, electric shock-like, tearing, burning, or characterized by increased pressure sensation in the rectum, aggravated by prolonged sitting and lying down for hours to days. The incidence is higher among women in the overall population, and more than 50% of patients are between 30 and 60 years old, of which only 29% go to the doctor, but it obviously affects work and study. In addition, the onset of pain can have a certain physiological cycle, with mild symptoms appearing in the morning, worsening in the middle of the day, and disappearing in the evening. The diagnosis of LAS can be made on the basis of symptoms alone. The diagnosis is much more credible if there is tension, tenderness or pain in the anorectal muscles when the puborectalis muscle is pulled backward. Tenderness occurs unevenly, mainly on the left side, and massage of this muscle usually causes discomfort. There are two levels of diagnosis: “highly suspicious” if symptoms are consistent and signs are present, and “suspicious” if symptoms are consistent but signs are absent. The clinical evaluation usually consists of a history, rectal examination, and exclusion of other diseases causing chronic anal pain. Many studies have reported increased anal canal electromyographic activity and pressure in the anal canal in patients with LAS. However, the criteria for anorectal manometry tests have not been clarified, and there is literature suggesting that pain relief is associated with decreased anal canal pressure, and studies have been done on cases of sphincter hypertonia (PMS and patients with descending perineal syndrome), which have had high puborectal muscle pressure resulting in pain. Nonspecific functional anorectal pain Fully compatible with the diagnostic criteria for chronic anorectal pain and does not cause tenderness when the puborectalis muscle is pulled from the posterior. Current cases are rare. Diagnosis of spasmodic proctalgia (PF) PF refers to a sudden sharp pain in the anal area that lasts for a few seconds or minutes and then disappears completely. The mechanism may stem from abnormal smooth muscle contractions, and patients with a family history of PF may be associated with hypertrophy of the internal anal sphincter.The etiology of PF is most often related to psychological disorders, and about 60% of patients have multiorgan symptoms in combination with irritable bowel syndrome, peptic ulcer, or inflammatory bowel disease. In addition to increased IASP, anal canal and sigmoid colon pressures are elevated. The pain has been reported to last more than 5 min in only about 10% of patients [8,9], and at the end of the attack the pain disappears completely as normal until the next attack. The duration of the attacks is uncertain and irregular, they may occur once in a few days or once in a few years, and they are infrequent, with 51% of patients having fewer than 5 attacks per year. The incidence in the population ranges from 8% to 18%, and only 17% to 20% of patients seek medical attention. The incidence of the disease varies between men and women. The age of onset is between 30 and 50 years in both sexes. A distinction should be made between LAS and spasmodic PF, as the former has a longer duration and more frequent onset, and there is a clear difference between LAS and the pain caused by fissures and hemorrhoids, which is vague and dull in nature, and is more likely to occur in sitting than in standing, and can be relieved by hot water baths.