Pain in the anal area, accompanied by blood in the stool, does not necessarily indicate rectal cancer. There are many causes of pain and bloody stools, which require identification and diagnosis through the color of the bloody stools, digital rectal examination, and colonoscopy. Common causes of bright red bloody stools or pain are mainly due to hemorrhoids and anal fissures. During the onset of rectal cancer, early stages generally do not involve pain in the anal area. It is mainly characterized by changes in bowel habits, or dark red blood in the stool in the middle to late stages. The tumor may grow larger, causing difficulty in defecation, and may even induce systemic symptoms such as weight loss, anemia, and intestinal obstruction.