The spleen and stomach

Both the spleen and stomach are situated in the middle jiao, and are externally - internally related via their channels. The spleen dominates transportation and transformation, and the stomach dominates reception. Reception and digestion of food mainly rely on the stomach, and the absorption and distribution of nutrient substance rely on the spleen. The stomach prepares the food for the spleen to transport and transform, whilst the spleen distributes nutrient substance to assist the stomach in moving body fluid. Dysfunction of the stomach in reception may give rise to poor appetite and an unpleasant and hungry sensation in the stomach. Dysfunction of the spleen in transportation and transformation may often lead to abdominal distension after eating and loose stools.

The spleen dominates ascending and the stomach dominates descending. The spleen distributes the essential substance of water and food up to the heart and lung. The stomach moves the digested water and food downwards. If the spleen qi descends rather than ascends, there may be diarrhea and prolapse of the rectum. If the stomach qi ascends rather than descends, there may be nausea, vomiting and hiccups. The physician Ye Tianshi of the Qing Dynasty ( 1644 - 1911 ) said : " The stomach dominates reception, and the spleen dominates transportation and transformation. The spleen is ' favorable ' when its ascending function is normal, and the stomach is ' favorable ' when its descending function is normal. "

The spleen is yin, prefers dryness and dislikes dampness. The stomach is yang, prefers moistness and dislikes dryness. Being yin and yang in nature respectively, each needs the other. When pathogenic dampness invades the spleen, it may injure the transportation and transformation function, and in turn, lead to the production of dampness. When pathogenic heat invades the stomach, it may consume the body fluid in the stomach, and deficiency of stomach yin may stir up heat of deficiency type in the interior. Since the spleen and stomach are mutually connected physiologically, they also affect each other pathologically. For instance, dysfunction of the spleen in transportation and transformation due to retention of dampness may lead to inability to ascend the clear, and affect the stomach function of receiving and descending. Clinical manifestations include poor appetite, nausea, vomiting, and fullness and distension of the epigastrium. Conversely, dysfunction of the stomach in descending the turbid, due to irregular food intake which causes retention of food, may also affect the function of the spleen in transporting, transforming and ascending the clear, giving rise to abdominal distension and diarrhea