In normal people, there is stool in the rectum, because the rectum is the terminal part of the human large intestine and the near terminal part of the human digestive system, which is usually 15 centimeters long. The main function of the rectum is to help promote defecation, because it can absorb part of the glucose, water and drugs, and can also secrete mucus to help normal defecation. However, human stools are present in the sigmoid colon, and the peristaltic movement of the colon during defecation will cause the stool to move downward into the rectal area. Then by the relaxation of the anal dilatation, the stool passes through the rectum and is discharged from the anus. So the normal person’s rectum is inside the residual stool, if the rectal area of the abnormal symptoms, should go to do anoscopy in time, and then timely treatment.