Anal cancer is a type of cancer that occurs in the tissues of the anus, which is the opening at the end of the digestive tract. It can develop from the cells lining the anal canal and may be linked to certain risk factors, including human papillomavirus (HPV) infection, smoking, and a weakened immune system. Symptoms may include pain, bleeding, or changes in bowel habits. Diagnosis typically involves a physical examination, imaging tests, and a biopsy to confirm the presence of cancer cells. Treatment options may include surgery, radiation therapy, and chemotherapy, depending on the stage and location of the cancer. Early detection is important for better outcomes.