Diyu has the effects of cooling and stopping bleeding (cooling and moisturizing the blood to prevent bleeding), detoxifying and astringing sores. It is used for blood in the stool, hemorrhoidal blood, bloody diarrhea, leakage (excessive menstrual flow or dribbling), scalded by water and fire, carbuncle, swelling and sores. Ground elm is the root of the Rosaceae plant ground elm. It has a bitter, sour and astringent flavor, and belongs to the liver and large intestine meridians. It can be used to treat hemorrhagic conditions caused by blood heat, such as blood in the stool, hemorrhage from hemorrhoids, leakage (excessive menstrual flow or dripping), etc.; it can also be used to treat burns from water and fire, eczema, canker sores and poisons. Ground elm can be used externally or taken internally. Internal use is mainly decocted with water, and external use can be boiled water for external washing. The ground elm for astringent hemostatic medicine, blood stasis bleeding should not be used; in addition, the spleen and stomach cold (spleen and stomach weak cold), in the qi subsidence (spleen and stomach qi deficiency, appearing visceral organs fall and other manifestations), cold dysentery and diarrhea and leakage of subluxation are not suitable for use. Patients with extensive skin burns should not use Diyu preparations for external use, there is a risk of drug-induced hepatitis.