Functions of the Stomach
Controls Rotting and Ripening of Food
- Stomach transforms the food and drink we ingest. "Rotting and ripening" is the process of fermentation which prepares the way for the Spleen to extract the refined essence from food.
- After the refined part of the food and fluids has been extracted by the Spleen, the Stomach passes the remainder to the Small Intestine for further separation and absorption.
Controls Transportation of Food Essences
- Together with the Spleen, the Stomach controls the transportation of the food essence to the whole body including limbs.
- Strong Stomach Qi: strong energy.
- Deficient Stomach Qi, weak food essences, and
- Stomach will not have Qi to transport them to the whole body, hence fatigue, and especially weak limbs.
- Stomach affects tongue coating.
- Tongue coating or "fur" is formed by some "turbid dampness" that is a by-product of the Stomach's rotting and ripening activity. This dirty dampness rises up to the tongue to form the coating.
- Thin white coating on tongue = Stomach is functioning properly. No coating or peeled coating = Stomach's digesting function is impaired and Stomach Qi and perhaps Yin severely weakened.
Controls the Descending of Qi
Stomach sends the transformed food down to Small Intestine for further separation. Therefore, in health, Stomach Qi moves downwards. If Stomach Qi fails to descend, food can stagnate in Stomach and cause feelings of fullness/distention, sour regurgitation, belching, hiccup, nausea and vomiting.
Causes of Stomach Qi failing to descend:
- Overeating, which "overwhelms" Stomach
- Liver invading Stomach (Five Element scenario)
Stomach is the Origin of Fluids
- Stomach needs plenty of fluids in order to perform its rotting and ripening function.
- Fluids themselves are actually derived from ingested food and fluids.
- Stomach ensures that part of food and drink goes to form essences (which are extracted by the Spleen).
- The Stomach ensures that the other part of food and fluids condenses to form body fluids. Hence, Stomach is important source of fluids.
In the Nei Jing, it states: "The Stomach likes wetness and dislikes dryness."
If Stomach fluids are abundant, digestion will be good, sense of taste will be normal. Deficient Stomach fluids (Deficient Stomach Yin): poor digestion, thirst, dry, cracked tongue.
Causes of deficient Stomach fluids:
- Eating large meals late at night
- Deficiency of Kidney Yin, or from long-term loss of fluids.
Stomach can suffer from Yin Deficiency (Deficient Fluids) or from Yang Deficiency (producing insufficient warmth to rot and ripen) or from Retention of Food (which can relate to either).
Stomach's Relationship with the Spleen
Stomach = Yang Earth. Spleen = Yin Earth. Close relationship Stomach Qi descends, Spleen Qi ascends.
Stomach likes wetness and dislikes dryness; Spleen likes dryness and dislikes wetness.
If Stomach too dry, Stomach Qi cannot descend and food cannot be moved down to Small Intestine. If Spleen too damp, Spleen Qi cannot ascend and fluids and food cannot be transformed. Stomach easily suffers from Excess, Spleen easily suffers from Deficiency. Stomach is prone to Heat, Spleen is prone to Cold (producing Dampness). Stomach tends to suffer from Deficiency of Yin, Spleen tends to suffer from Deficiency of Yang.