Perianal abscess: It is an abscess formed by acute and chronic infection of the perianal rectal space due to the spread of infection and septicemia in the anal glands. It is characterized by rapid onset, severe pain and high fever in most young adults aged 20-40. It is a clinical emergency and should be treated as early as possible to avoid aggravation of the condition. Clinical manifestations: The disease is more common in men than women, especially in young adults. The lump around the anus is mildly painful, or the pain may be felt as stabbing pain or swelling in the anus, followed by increased pain, increased size of the lump around the anus, redness, swelling, tenderness and hardness, accompanied by different degrees of fever, lethargy, loss of appetite, constipation and other symptoms. Abscesses can be formed locally in about a week, and there can be local fluctuation after abscess formation. If the abscess breaks down by itself or after incision, yellowish-white pus may flow out, after which the pain may gradually be relieved or disappear and the body temperature may drop. Other symptoms may also be relieved. The symptoms vary depending on the location and depth of the abscess. For example, abscesses in the interstitial space above the anal raphe are deep and hidden, with heavy systemic symptoms but light local symptoms, while abscesses in the interstitial space below the anal raphe are shallow, with obvious local redness, swelling and heat pain but light systemic symptoms.