In life, there are often people who, because they are really busy at work or because the conditions do not allow them to do so, even if they have the urge to defecate, they will artificially tighten the anus until the urge to defecate disappears, which professionally belongs to the “retrograde peristaltic” reflex. If the cerebral cortex frequently inhibits defecation, on the one hand, the sensitivity of the rectum to feces is reduced; on the other hand, feces stays too long in the rectum and sigmoid colon, water is excessively absorbed and feces becomes dry, resulting in stubborn constipation. The highest “command” of the human body to control defecation – the cerebral cortex has a regulatory role in the sacral spinal defecation center. When artificially trying to inhibit defecation, the external anal sphincter will contract strongly, and the contracted external sphincter will compress the internal sphincter, causing the internal sphincter to contract, at this time, due to the inherent characteristics of smooth muscle (smooth muscle in the gastrointestinal system), the internal sphincter contraction will reflexively expand the rectum, increasing the rectal space, and more feces will be retained in the rectum. The longer the stool stays, the more water is absorbed by the intestinal wall, so the more likely it is to cause constipation, and in some cases, the patient has no desire to defecate. Therefore, it is very beneficial to avoid constipation by having a bowel movement. In addition, because defecation is a complex, coordinated, temporal conditioned reflex involving the cerebral cortex, it is important to develop the good habit of regular defecation and not to easily break your own rules, which is not only very important for defecation, but also vital to maintain the stability of your “biological clock”.