There is no such thing as yin deficiency and fire (deficiency of yin and essence in the body, resulting in hyperactive fire), what kind of medication can be used to regulate loose stools (thin and unshaped feces). Generally speaking, people with yin deficiency and fire exuberance will not have loose stools. If there is evidence of fire exuberance with loose stools, it may be evidence of heat above and cold below, or damp-heat obstruction (accumulation of dampness and heat to form a stagnant blockage), which can be treated with Wu Mei Pills, Ge Gen Scutellariae Linnaeus Pills, and so on. Symptoms of upper heat and lower cold (heat in the upper part and cold in the lower part) are mostly caused by misuse of laxatives or deficiency of kidney yang (lack of yang in the kidneys), and too much cold forcing yang to float upwards, etc. Clinically, there are common symptoms such as dry mouth and throat, dryness of the eyes, and dizziness and distension of the head, etc., and the treatment should be to regulate the heat and cold evenly. The symptoms of damp-heat obstruction are mostly caused by the feeling of damp-heat evil, or overeating spicy and greasy things, etc. Clinically, it is common to see burning pain in the epigastrium (abdomen), embarrassment in bowel movement, unpleasant diarrhea, yellow and sticky stools, and burning in the anus, etc. The treatment is to clear away the heat and promote dampness (removing heat and dampness from the body). Wu Mei Wan has the effects of easing the liver and regulating the middle, clearing the upper part of the body and warming the lower part of the body, treating headache, abdominal pain like strangulation, which occurs and stops at any time, and cold hands and feet. Note that this drug contains epiphyllum, and is contraindicated in pregnant women. Scutellaria baicalensis Pill is effective in clearing away heat and removing dampness, detoxicating and stopping diarrhea, treating intestinal tinnitus and diarrhea, with foul-smelling diarrhea, yellowish color and sticky texture, and burning pain in the anus. Note that it is contraindicated for those with deficiency of spleen and stomach (weak and cold spleen and stomach). If you have any of the above symptoms, it is recommended to take scientific treatment under the guidance of a doctor. If you need to take the above medicines, it is recommended to consult your doctor.