The lung and the large intestine are the contents of Chinese medicine’s Tibetan elephant doctrine. Chinese medicine believes that the five internal organs are Yin and are located in the inner part of the body, while the internal organs are Yang and are located in the outer part of the body, so the internal organs constitute the relationship between each other. The relationship between the internal organs is also called yin and yang, because the internal organs are yin and the internal organs are yang, and the internal organs are in the inside and the internal organs are in the surface, a table and a lining, a yin and a yang cooperate with each other, which constitutes the relationship between the internal organs. The lung and large intestine are related to each other through the meridians, and the internal organs are related in function. The lung and large intestine are related, the descending function of the lung helps the large intestine conduct function, and the normal function of the large intestine conduct is also conducive to the descent of the lung. If the large intestine out of the reality of heat, the internal Qi can not pass, can affect the descent of the lung and produce symptoms such as chest tightness, wheezing and coughing. If the lung loses its descent, the fluid cannot go down to the large intestine and symptoms such as difficulty in passing stools and difficult stools will occur.