The Stomach channel is the principal yang channel of the front of the body, which is unusual in itself: yang channels in this system generally run on the outer and posterior surfaces, and the Stomach is the conspicuous exception, descending the face, chest, abdomen and the front of the leg to the second toe. The tradition explains the anomaly by function rather than geography, since the Stomach is described as the origin of the acquired qi, what the body makes from food, as against the inherited qi stored by the Kidney.
Its best known point is Zusanli, Stomach 36, below the knee. The name is usually rendered Leg Three Li, a li being a unit of distance, and the classical literature attaches to it a reputation for restoring a tired traveller enough to walk three more. It is among the most heavily studied points in the modern acupuncture literature and among the most heavily used in the classical, and the atlas records both facts without asserting an effect.
The Stomach pairs with the Spleen as the yang and yin of the Earth phase, and the two together carry most of what Chinese medicine says about digestion, appetite and the transformation of food. That is a statement about the tradition's own model. It is not an anatomical claim, and nothing here is medical advice or a reason to defer a medical question to anyone but a clinician.