Possible causes of flat stool include physiological factors such as high water content in feces; pathological factors such as hemorrhoids, intestinal obstruction, intestinal inflammation and so on. 1. Physiological reasons: If the feces are flat and soft, it may be due to the high water content of the feces, which may be caused by drinking enough water, so there is no need to worry too much. 2. Hemorrhoids: clinically known as hemorrhoids, is due to the lower end of the rectum or the anal canal veins congestion and enlargement of the result, due to the presence of swelling, resulting in the stool is squeezed when discharged, so there is a flat stool, but also can be accompanied by pain in defecation, defecation bleeding and other symptoms. 3. Intestinal obstruction: if there are tumors, hernia, intestinal adhesions, etc. in the intestine, the feces may also be squeezed, forming flat stools. 4. Intestinal inflammation: If the intestinal tract is inflamed due to viral or bacterial infections, the exudate from the intestinal tract may increase due to the effect of the inflammatory lesions, which may also lead to flat stools. It is recommended to go to the regular hospital in time to find out the cause of the flat stool and treat it in time.