The rectum of a human being is about 10~15 centimeters, and there are some individual clinical differences between people of different heights and body types. The rectum belongs to the end of the digestive system, connecting the sigmoid colon at the upper end and the anal canal at the lower end, and most of it is located in the pelvic cavity, with a length of about 10~15 centimeters. The main daily role is to store and control bowel movements, as well as to absorb water from the stool. The proximity of the rectum to the anus may cause infectious diseases such as proctitis, or malignant diseases such as rectal cancer. If there are uncomfortable symptoms, you should go to the hospital in time for the appropriate auxiliary examination, such as rectal finger diagnosis proctoscopy and other tests, to diagnose the cause of the disease and active treatment.