The common clinical causes of long and thin stools are intestinal polyps or intestinal cancer, hemorrhoids, constipation and so on. 1. Intestinal polyp or intestinal cancer: when intestinal cancer tumor or intestinal polyp grows in the intestinal tube, it will occupy the air of the intestinal tube, which will cause the organism to have difficulty in defecation and abnormal shape of stool. 2. Hemorrhoids: this disease is clinically divided into internal hemorrhoids and external hemorrhoids, the former refers to the soft mass formed by the expansion and varicose of the blood vessel plexus under the mucous membrane at the end of the rectum above the dentate line of the anal canal, which will take up part of the volume of the anal canal, thus resulting in the change of defecation habits and shape of the stool of the diseased people. 3. Constipation: People suffering from this disease usually drink less water and eat less dietary fiber, which causes the feces to stay in the colon for a long time and absorb a lot of water, thus the volume of feces will be reduced and it is difficult to be discharged. It is recommended that people with this condition should go to the hospital in order to clarify the cause of the disease and have targeted treatment.