Spleen and stomach are the foundation of the day after tomorrow, which is of great significance in disease prevention and health preservation. Ancient physicians believed that "all diseases are due to spleen and stomach failure". Therefore, attention should be paid to protecting the spleen and stomach in daily life, paying attention to diet and nutrition, and taking care of the spleen and stomach when treating diseases. How does TCM know "small intestine"? Traditional Chinese medicine believes that the small intestine belongs to the viscera, and its main function is to "absorb excess, dissolve matter and secrete turbidity". (1) The harmonious product between the host and the receptor means that the small intestine receives the food preliminarily digested by the stomach, and can keep it for a certain period of time for further digestion and absorption, thus turning Shui Gu into subtle. (2) The food digested by small intestine is Shui Gu subtle and food residue, which absorbs Shui Gu subtle and transports food residue to large intestine, and absorbs a lot of water while absorbing Shui Gu subtle, so it is also called "small intestine main fluid". In addition, the turbidity-expelling function of small intestine is also related to urine volume. If the function of excreting and clearing turbidity in the small intestine is normal, the urine and stool are normal; If the function of the small intestine to excrete turbid gas is abnormal, the stool becomes thinner and the urine becomes shorter, that is to say, the amount of water in the small intestine is related to the amount of urine. In fact, the functions of small intestine in receiving, excreting and clearing turbidity are the concrete manifestations of the function of spleen and stomach in lifting turbidity. Therefore, the dysfunction of small intestine can cause abdominal distension, abdominal pain, vomiting, constipation and so on. It is caused by turbid qi, and it can also cause loose stool and diarrhea caused by clearing qi. How does Chinese medicine know "large intestine"? Traditional Chinese medicine classifies the large intestine as fu organs. The large intestine lives in the abdomen, with the upper mouth close to the small intestine at the door and the lower end close to the anus. Because it has meridians with the lungs, it belongs to the exterior and interior. The main physiological function of the large intestine is to conduct dregs. The large intestine receives the food residue left by the foul gas secreted by the small intestine, and then absorbs excess water to form feces, which are excreted through the anus. The conduction change of large intestine is an extension of the function of reducing turbidity in stomach, and it is also related to the reduction of turbidity in lung. In addition, the slag guiding function of the large intestine is closely related to the body fluid in the human body. Deficiency of body fluid due to kidney deficiency or burning of body fluid due to gastrointestinal heat can lead to poor stool conduction, dry stool and constipation. How does TCM know "kidney"? Traditional Chinese medicine believes that the kidney is dirty and contains "congenital essence", which is the source of yin and yang of viscera and the source of life, so it is called "congenital essence". The main function of the kidney is to store essence, control growth, development, reproduction and water-liquid metabolism. The kidney controls the bone to produce marrow, and the external glory is in the hair, and it is enlightened by the ear and the second yin. Storing essence is the main physiological function of kidney, and essence in kidney is the basis of life activities and plays an extremely important role in all aspects of physiological activities. Kidney governing body fluid mainly refers to the gasification function of kidney essence, which plays an extremely important role in regulating the distribution and excretion of body fluid and maintaining the metabolic balance of body fluid. In fact, the kidney governs the bone and produces marrow, which is an important part of the essence in the kidney and can promote the growth and development of the body. The rise and fall of essence in kidney not only affects the growth and development of bones, but also affects the filling and development of spinal cord and brain pulp. "Tooth except bone", tooth is homologous to bone, and tooth is also nourished by essence in kidney. If the kidney is full of essence and the teeth are firm, it is not easy to fall off. Insufficient essence in the kidney, teeth are easy to loosen, and even fall off early. The kidney begins to know the second yin (external genitalia and anus), so frequent urination, enuresis, urinary incontinence, oliguria or anuria are all related to the abnormal gasification function of the kidney. Excretion of feces is the function of spreading dregs of large intestine, but it is also related to the gasification of kidney. For example, if the kidney yin is insufficient, the intestinal juice will dry up, causing constipation, while the kidney yang is damaged, the gasification is weak, and yang deficiency causes constipation.