Alum is astringent and difficult to serve, should not be taken internally in excess, easy to vomit; people with weak stomachs should be cautious. Alum, alum, is crystallized from the processing and refining of alum stone. It is sour, astringent and cold in nature. Attributed to the lung, spleen, liver, large intestine meridian. It is used externally to detoxify and kill insects, dry dampness and relieve itching; internally to stop bleeding and diarrhea, and to dispel wind and phlegm. Externally used for eczema, scabies, prolapse of anus, hemorrhoids, pus in the ear; internally used for prolonged diarrhea, blood in the stool, leakage (excessive menstrual flow or dripping), epilepsy. Alum with chebula can enhance the efficacy of astringency to stop diarrhea (relieving diarrhea by enhancing the astringent function of the intestines). It is suitable for prolonged diarrhea, prolonged dysentery, slippery; alum with andrographis can enhance the efficacy of astringent sores, insecticide, detoxification. Externally, it is suitable for wet sores and scabies, itching, yellow water. Patients are advised to use the drug under the guidance of a doctor.