Stomach yin, opposite to stomach yang, refers to the yin fluids of the stomach and has the functions of calming, moistening, and nourishing. It is the substantial foundation of receiving, digesting, and absorbing what one eats, transmitting essential qi to the spleen, and nourishing other organs. The stomach has preference for moisture and is averse to dryness. Consequently, sufficient stomach yin fluids help the stomach to digest and absorb food and water, and propel digested food downward. Digestion and absorption not only requires stomach qi and stomach yang to propel food and transmit water, but also requires yin fluids to moisten the stomach. Adequate stomach yin helps maintain digestive and downward-propelling functions of the stomach.