Thin stool is one of the manifestations of bowel cancer, but having this symptom does not necessarily mean that it is bowel cancer. This symptom is more often seen in diseases such as enteritis, intestinal dysfunction or intestinal polyps. Usually, the main manifestations of bowel cancer are alternating diarrhea and constipation, as well as abdominal pain and blood in stool. If the mass is large and causes narrowing of the intestinal cavity, or if the occupancy is relatively close to the anus, this symptom of thin stool will appear. In addition to cancer factors, patients with chronic constipation can also have thin stools due to dry stool adhering to the intestinal wall. Benign intestinal lesions, such as intestinal polyps, can also cause thin stools. In addition, thin stools can also be caused by intestinal dysfunction, diarrhea, or thin stools caused by oversized hemorrhoids that prevent stool from being passed. Patients are usually advised to go to a hospital gastroenterology department for a colonoscopy to clarify the diagnosis. After the diagnosis is confirmed, patients with thin stools should follow medical advice for relevant treatment and pay special attention to regular diet and supplementation in daily life. If abnormal symptoms occur, prompt medical attention is recommended.