Gas discharged from the anterior orifice is therefore called "Yinchui" (Yin blowing). Gas discharged from the posterior orifice follows the normal path of the Large Intestine, hence it is called "Zhengxuan" (Normal rumbling). This refers to the Qi in the Stomach descending and leaking out through the collateral pathway of the anterior orifice, while simultaneously producing rumbling sounds through the normal pathway of the posterior orifice. This occurs because the Stomach receives food and the Spleen transforms it; however, due to dryness of the fluids in the Large Intestine resulting in constipation, the Grain Qi becomes excessive. The normal transmission of Grain Qi in the Large Intestine is insufficient, causing Qi and water metabolism products to burst forth through the branching pathways of the Small Intestine. Excess conditions lead to flatus; without promoting bowel movement to allow Grain Qi to descend smoothly, the condition cannot be resolved. However, if purgative agents are administered, this unjustly burdens the Spleen and Stomach, inevitably leading to an inability to eat and abdominal distension. Therefore, Pig Fat (Zhogao) which lubricates the intestines and intestines, and Hair Ash (Luanfa) which nourishes blood, are boiled together to make a decoction. Thus, the dryness and hardness are moistened and relieved downward, Grain Qi is pacified, and the symptoms of Zhengxuan will cease naturally. How could Yinchui persist? Mr. Li of Qiantang stated that Zhengxuan is merely the rumbling sound associated with Yinchui. Mr. Li Xu changed "Zhengxuan" in the original text to "Zhengjie" (Normal knotting), both interpretations being incorrect.