The composition of Bai Tou Weng San is mainly composed of Bai Tou Weng and Huang Lian as the ruling herb, together with Xi Cao Root, Di Yu and Roasted Licorice, all of which are mainly heat-clearing herbs with the effect of clearing heat, detoxifying and stopping dysentery. Huanglian has the effect of clearing heat and fire, dampness and detoxification, both of which are important for treating dysentery. Radix Rehmanniae and Radix Elm have the effect of nourishing the blood and stopping bleeding, activating blood circulation and resolving blood stasis. Roasted licorice can play a role in harmonizing the drugs, reducing the toxicity of each drug, so the main role of whiteheaded wormwood is to detoxify and stop dysentery, used for various bleeding dysentery and prolapse of the anus and other septicemia.