There are many reasons for the thinning of stool. The first one is constipation. When constipation occurs, patients often have difficulty in defecation, dry stool, and thin stool. In serious cases, sheep feces may appear. In this case, the symptoms can often be alleviated after active bowel soothing treatment, drinking more water and eating more vegetables and fruits rich in dietary fiber. In addition, the thinning of stool is also related to colorectal tumors. In this case, patients are often accompanied by weight loss, emaciation, anemia, fatigue, malnutrition and other symptoms. It is suggested that further colonoscopy should be performed to make a clear diagnosis.