In Traditional Chinese Medicine (TCM), Xiao Shi belongs to the 'Purgative herbs that drain downward' category. The herbs in this category are those whose main purpose is to treat constipation. The fact they're 'purgative' means that they do so by removing Excess Heat in the Intestines and/or Stomach. As such all herbs in this category are Cold in nature, in order to cool the Heat.

Furthermore Xiao Shi is Warm in nature. This means that Xiao Shi tends to help people who have too much 'Cold' in their body, although with less effect than a plant that would be Hot in nature. Balance between Yin and Yang is a key health concept in TCM. Those who have too much Cold in their body are said to either have a Yin Excess (because Yin is Cold in nature) or a Yang Deficiency (Yang is Hot in Nature). Depending on your condition Xiao Shi can help restore a harmonious balance between Yin and Yang.

Xiao Shi also tastes Bitter and Salty. The so-called 'Five Phases' theory in Chinese Medicine states that the taste of TCM ingredients is a key determinant of their action in the body. Bitter ingredients like Xiao Shi tends to have a cleansing action on the body by clearing Heat, drying Dampness and promoting elimination via urination or bowel movements. On the other hand Salty ingredients tend to have a draining effect in the body because they clear accumulations, remove Phlegm and soften hard lumps.

The tastes of ingredients in TCM also determine what Organs and Meridians they target. As such Xiao Shi is thought to target the Spleen and the Heart. In TCM the Spleen assists with digestion, Blood coagulation and Fluids metabolism in the body. In addition to regulating Blood flow, the Heart is believed to be the store of the 'Mind' which basically refers to someone's vitality.