The Yang complement to the Yin-Spleen is the Stomach, and among all the organs, these two probably share the closest relationship. The Stomach is the essential assistant to the Spleen in that it receives and then ‘rotts and ripens’ food so that the Spleen can transform it into pure Qi and nourishing Blood.
Whereas the Spleen’s function is to raise Qi, the Stomach is responsible for descending Qi so that food moves through the rest of the digestive tract. When this function is weak, abdominal fullness, acid regurgitation, nausea, vomiting or hiccups are the result. The balance between the Spleen’s upward movements and the Stomach’s downward movements are crucial in the proper movement of Qi throughout the rest of the body and as such the two are considered the central axis of the body.