Pain in the back of the anus for two months may be associated with conditions such as hemorrhoids, perianal abscess, anal fistula, malignant tumor, and anal fissure. 1. Hemorrhoids: Patients with hemorrhoids may have symptoms such as anal pain, purplish-red meatballs in the anus, accompanied by an itching sensation. 2. Perianal abscess: If the anal gland area is infected, it will spread along the periphery, thus forming a perianal abscess. It is characterized by a bulging mass in the anal area, with severe pain, and the swelling will grow bigger and bigger. 3. Fistula: If the perianal abscess is not controlled, it will gradually form an anal fistula, and in severe cases, it will form a complex anal fistula, with multiple fistulas. 4. Malignant tumor: if the patient has malignant tumor, such as anal cancer, it will lead to the violation of the nerves around the anus, causing severe pain. 5. Anal fissure: if the patient’s stool is too dry, or bad life habits, it may cause the skin around the anal canal to be torn, causing pain. Considering the complexity of the causes, patients should go to the hospital in time, and actively cooperate with the doctor’s examination and treatment, to avoid delaying the aggravation of the condition.