Six fu organs are the general names of gallbladder, stomach, small intestine, large intestine, bladder and triple energizer. Their physiological function is "transmitting chemicals", and their physiological characteristics are "purging without hiding" and "being solid but not full". Food and drink enter the stomach through the esophagus, decompose in the stomach, pass down to the small intestine, and secrete turbidity through the differentiation of the small intestine. The clear ones (subtle and body fluid) are absorbed by the spleen, transferred to the lungs, and scattered throughout the body to meet the needs of life activities of zang-fu organs, meridians and collaterals; The turbid ones (dregs) are released into the large intestine, and through the conduction of the large intestine, stool is formed and excreted; The waste liquid is gasified by the kidney to form urine, which penetrates into the bladder and is excreted.