The rectum is the most terminal part of the large intestine, measuring about 15-16 cm in length, and it runs from the sacrum and coccyx down through the pelvic septum to the end of the anus. The upper part of the rectum in the pelvic septum is called the rectal pelvis. The lower part of the pelvic section has a shuttle-shaped enlargement, which is the rectal pot belly. The main function is to store feces, and there are 2-3 semilunar transverse rectal folds in the pot belly to support feces. The narrowing of the lower part of the pelvic septum is called the recto-anal portion or anal canal. The external outlet directly connected to the anal canal is the anus. In addition, the rectum is surrounded by internal and external sphincters, whose main role is to control defecation by contraction and relaxation of the sphincters. The rectal and anal regions will have a very visual response to the individual’s dietary life. Long-term poor eating habits or sedentary, standing, squatting, etc., it is easy to form anus-type diseases, need to pay particular attention.