The difference between Da Cheng Qi Tang and Xiao Cheng Qi Tang is mainly reflected in the composition, main treatment and efficacy. If the patient has a need for medication, it is recommended to consult a physician to clarify the cause of the disease to choose treatment measures, do not self-medication. According to “The Treatise on Typhoid Fever”, Dachengqi Tang is mainly composed of rhubarb, Houpu, Citrus aurantium, and manganese nitrate, and has the ability to make the stools smooth, and all the symptoms will be relieved. It can treat the following symptoms. 1. Yangming viscera solid evidence, the main clinical manifestations of the evidence for the stool blockage, exhaust more frequent, abdominal distension and pain can not be pressed, or pressed hard, and even the whole body hot flashes (a burst of fever), confusion, babbling, sweaty hands and feet, and so on. 2. Heat knot bypassing the flow of evidence, the main clinical manifestations of this evidence for the stool color pure green, pungent odor, and a large number of undigested food, pain around the umbilicus and abdomen, pressing the hard lumps, dry mouth and tongue and so on. 3. The main clinical manifestations of this syndrome are cold limbs, generalized fever, red face, dry mouth and lips, red and short urine, dry stools, unconsciousness, and so on. Small Chengqi Tang is mainly composed of rhubarb, thick park, hedgehog, with light down the hot knot, in addition to the fullness of the efficacy of the elimination of plaque, the main treatment of Yangming viscera solid evidence, the main clinical manifestations of the evidence for the confusion, babbling, constipation, chest and abdominal distension, yellow tongue, or dysentery at the beginning of the abdominal distension, abdominal pain, after the weight of the rush (uncomfortable in the lower abdomen, very much want to defecate, defecation after the feeling of incompletion), and so on. The use of drugs should be under the guidance of a doctor, not self-medication.