Anal absorption of drugs is faster, mainly in the anus is given to dissolve the drug quickly absorbed into the blood to play the efficacy of the drug, but not as fast as the sublingual route of the effect of sublingualization. Anal drug delivery is mainly through the anus will be sent to the rectum, through the rectum stabilization, secretion fluid, etc. will be dissolved, relying on the rectal mucosa reabsorption effect of the drug can be rapidly absorbed into the blood and play the efficacy of the drug. Rectal drug delivery methods are retained enema method, rectal drip method, suppository insertion method, the effect of the drug are more rapid. However, not all drugs administered anally have a rapid onset of action. For some diseases, such as hypertension, sublingual administration of drugs has a rapid onset of action; for some people, intramuscular injection may have a faster onset of action than anal administration of drugs for the treatment of fever.