Bowel cancer mainly takes colon cancer and rectal cancer as the most common. Early colorectal cancer and rectal cancer do not have obvious symptoms, while middle and late stage colorectal cancer mainly manifests with changes in bowel habit and fecal character, abdominal pain, abdominal mass, intestinal obstruction and systemic symptoms. 1. Change of defecation habit and fecal character: it mostly manifests as increased frequency of defecation, diarrhea, constipation, feces with blood, pus or mucus. At the same time, rectal cancer may also manifest rectal irritation signs such as urgency and heaviness, incomplete defecation and frequent urge to defecate. 2. Abdominal pain: colon cancer is often persistent hidden pain with inaccurate localization, or only abdominal discomfort or bloating. Rectal cancer is mostly lower abdominal pain. 3. Abdominal mass: due to its location, colon cancer may have abdominal mass, which is mostly the tumor itself, while rectal cancer does not have this manifestation. 4. Bowel obstruction: colon cancer usually manifests as chronic low-level incomplete bowel obstruction, which mainly manifests as abdominal pain, abdominal distension and constipation. 5. Systemic symptoms: patients may have anemia, emaciation, fatigue, cachexia, etc. When invading other parts of the body, patients may also have the performance of corresponding parts of the body, e.g. if rectal cancer invades prostate and bladder, patients may have the performance of frequent urination, urgency of urination, hematuria, etc. The above are the symptoms of most people in the middle and late stages. The above are the main manifestations in the middle and late stages of most people, not all of them will appear, and not all of the above symptoms will appear. As early symptoms are hidden, in order to avoid aggravation of condition and delay of treatment, if there is any discomfort and suspicion of recto-colonic cancer, it is recommended to seek medical treatment in time, improve relevant examination, clarify or exclude malignant tumors, and take therapeutic measures as early as possible under the guidance of specialists.