Drugs that help defecation are clinically called laxatives and are a class of drugs that promote the defecation reflex or make defecation smooth. According to the action and mechanism, they are divided into volumetric, stimulating, lubricating and swelling laxatives. For example, lactulose, polyethylene glycol powder, sodium carboxymethylcellulose granules, magnesium sulfate, etc., which are commonly used clinically for oral administration, as well as topical opiates, glycerin, and traditional Chinese medicine, such as rhubarb and senna. The clinical selection of drugs is mainly based on different types of constipation, such as lactulose for chronic functional constipation, and corkage for hypotonic constipation, and magnesium sulfate for acute constipation. These drugs can only temporarily solve constipation, not the root cause, to find the cause of targeted treatment, these drugs can not be used for a long time.