What causes pain in the anus during bowel movements?

Pain during bowel movements may be caused by conditions such as perianal abscess or anal fissure. A perianal abscess, which results from a pus-forming infection in the soft tissues around the anus, typically causes discomfort including pain and a sensation of heaviness in the anal area, leading to pain during defecation. In cases of anal fissure, the skin around the anus is irritated by stool during bowel movements, often worsening the tear and causing anal pain.