In the early stages of rectal cancer, there are no obvious symptoms. Only when the condition progresses to a certain extent do some clinical symptoms appear. The first is a change in bowel habits or the nature of the stool. The second possible symptom is abdominal pain. The third possible outcome is intestinal obstruction. The fourth symptom occurs when the tumor develops to a certain extent, and lumps can be felt in the abdomen. The fifth point includes possible symptoms of systemic poisoning such as anemia, weight loss, fever, and weakness. The sixth point is that in the advanced stages of rectal cancer, some metastatic lesions may appear, such as extensive pelvic metastasis and infiltration, leading to pain in the sacral area and sciatic neuralgia; if areas like the vaginal, rectal mucosa, or bladder mucosa are involved, there may be vaginal bleeding or blood in the urine, resulting in conditions like rectovaginal or rectovesical fistulas.