There is no such thing as the best time for an enema; enemas are only appropriate when indicated and there is no specific time requirement. Enema is an invasive professional operation, through the saline or other medicinal solution into the intestinal tract to defecate, defecation or treatment of disease and so on. It includes a variety of methods such as clean enema, retention enema, enema for infection in the intestines, etc. Different methods are chosen for different conditions. Enemas have the potential to cause infections, perianal breakage and bleeding, and other adverse reactions, so they should only be used when indicated. Enema is currently mainly used to solve constipated people’s defecation difficulties as well as preoperative patient’s intestinal preparation, etc., and should not be used arbitrarily. Enema needs to be operated by professional doctors or nurses, before enema need to consult a professional doctor to determine whether there is a need for enema, it is recommended that patients go to a regular hospital.