Anal pain is mainly a symptom of pain in and around the anorectum, which is common to many anorectal diseases. For example, anal fissure, anal sinusitis, thrombosed external hemorrhoids, paranal abscess, embedded internal hemorrhoids, external hemorrhoid edema, anorectal cancer, anal foreign body injury, and post-anorectal surgery. The nature, degree and accompanying symptoms of pain vary. (1) Anal fissure Pain caused by anal fissure is periodic, mostly during or after stool, mainly due to fecal irritation and expansion of ulcer fissure. The pain is paroxysmal burning pain or cutting pain, which can last for several minutes; after the passage of feces, the pain is reduced. In addition, due to the stimulation of defecation, the internal sphincter muscle may be in continuous spasm, causing severe and persistent pain in the ulcer fissure; it often lasts for several hours, making the patient restless and in great pain; in severe cases, the pain may last for more than 24 hours. In addition to pain, anal fissures are often accompanied by bleeding and constipation. (2) Anal sinusitis is usually a slight pain and swelling in the anal region, and burning pain in the anal region due to the pressure of feces on the inflamed anal sinus during defecation, and if the sphincter is contracted due to stimulation, the pain increases and radiates to the buttocks and the back of the femur. It is often accompanied by a small amount of purulent or mucus discharge overflowing, smelly, and can cause perianal dampness, itching and other discomfort over time. (3) Thrombosed external hemorrhoid The milder ones have foreign body sensation, mostly accompanied by swelling and pain. Due to the breakage of perianal veins, blood clots become thrombus and appear under the outer skin of the anus as bruised round hard nodules, usually at 3 and 9 o’clock in the truncated position. (4) Paranal abscess The pain is mainly swelling and painful, and the pain is chicken-peck-like when pus is brewed. Due to various factors such as the location of paranal abscess, size of abscess, pathogenic bacteria and the resistance of the patient’s body, the symptoms and signs appear differently. The common ones include perianal subcutaneous abscess, sciatic rectal fossa abscess, pelvic rectal fossa abscess, retrorectal abscess, and tuberculous abscess. All of these abscesses are usually semi-present with fever, chills, constipation, and dyspareunia, except for the main symptoms, which vary. Unlike other sites, about 90% or more of paranal abscesses can form anal fistulas, which have a longer course. (5) Internal hemorrhoids are mainly painful and burning, mostly due to varicose hemorrhoid veins, broken blood circulation and thrombosis, resulting in restricted tissue circulation and prolapse outside the anus, which cannot be retracted. Therefore, it needs to be retracted or treated surgically as soon as possible, otherwise the surface mucosa is prone to bleeding, breakage, and even complications of infection. (6) External hemorrhoid edema is mainly swollen and painful, and is characterized by a limited mass at the edge of the anus, which is hard, smooth, shiny and painful to touch. It is mostly caused by straining, struggling during stool or surgical stimulation. (7) Rectal cancer is painless in the early stage, but later on, due to the enlargement and rupture of the mass, it may lead to swelling and vague pain in the anus, and it is common to have symptoms such as change in stool habit, pus and blood stool, abdominal distension, abdominal pain and emaciation. Patients with the above symptoms should consult a specialist for diagnosis and treatment in a timely manner. (8) Anal foreign body injury Most of them are caused by traumatic foreign body residue or improper diet, fish spur, bone fragment embedded in the rectum of the anal canal, so it is necessary to ask the doctor to carefully examine and remove the foreign body, and the pain can be relieved. If the retention time is too long, it may cause local infection. (9) Anorectal neurosis, pubic neurological syndrome and inflammation of the rectum can cause anorectal pain, which often requires clinical attention and differentiation. Above (1), (2), (5) and (6) are mostly pain during defecation; (3), (4), (7) and (8) are mostly persistent pain; and (9) is intermittent pain. Anal pain is one of the most common symptoms, so it is necessary to make a clear diagnosis, find the cause and examine the cause for treatment. Otherwise, it will not only fail to relieve the pain, but also delay the treatment.