[General Principle] Zhang Zhongjing stated: If a patient presents with no typical exterior or interior syndromes, but has fever and has not had a bowel movement for seven to eight days, even if the pulse is floating and rapid, purgation may be used. If purgation has already been administered but the rapid pulse persists, the internal heat combines with stomach qi, leading to excessive digestion and hunger. If there is still no bowel movement after six or seven days, it indicates the presence of blood stasis. The Dandang Tang (Dang Gui Decoction) is appropriate. If the rapid pulse persists and diarrhea becomes unceasing, it is likely accompanied by heat resulting in pus and blood in the stool.

[Commentary] Shen Jin'ao noted: Unceasing heat-type diarrhea inevitably leads to pus and blood in the stool. This occurs because the patient previously had accumulated blood stasis, resulting in both internal and external heat, excess Yang and deficient Yin, causing injury to the Yin collaterals. This condition arises from heat flowing downward following purgation, leading to pus and blood in the stool.

[General Principle] Zhang Zhongjing stated: In Yangming disease, bleeding from the anus accompanied by delirium indicates that heat has entered the Blood Chamber (Xue Shi). If only the head sweats, the Qimen acupoint should be needled.

[Commentary] Wang Kentang stated: The Chong Mai (Penetrating Vessel) is the Sea of Blood, also known as the Blood Chamber. Both men and women possess it. In men, bleeding and delirium; in women, alternating chills and fever resembling malaria, are all caused by heat entering the Blood Chamber, forcing blood downward, resulting in heat-accompanied diarrhea. The pulse carrying blood may be intermittent and rapid, or deep and hidden. When blood heat intertwines, the pulse becomes surging and vigorous. Generally, this manifests more often on the left hand in men and the right hand in women. There are also cases of diarrhea with pus and blood caused by Yin-cold pathology, which results from deficiency-cold in the Lower Jiao, instability of the intestines and stomach, and failure to separate the clear from the turbid, leading to pus and blood in the stool. These two conditions represent one of Blood Heat and one of Blood Cold; they must be carefully distinguished during clinical practice.

[General Principle] Zhang Zhongjing stated: In Yangming disease, if tidal fever and hard stool are present, Da Chengqi Tang (Major Order the Qi Decoction) may be given. If the stool is not hard, it should not be given. If there has been no bowel movement for six or seven days and dry feces are suspected, the method to confirm is to administer a small amount of Xiao Chengqi Tang (Minor Order the Qi Decoction). If gas passes after the decoction enters the abdomen, dry feces are present, and purgation can proceed. If gas does not pass, the stool is merely hard at the beginning and loose at the end; purgation is contraindicated. Purgation would lead to abdominal fullness and inability to eat. If the patient desires water, giving it may cause hiccups. Subsequent fever will likely result in hard but scanty stool; Xiao Chengqi Tang should be used to harmonize. If gas does not pass, purgation must be strictly avoided. In Yangming disease, after purgation, if there is inner restlessness and agitation indicating dry feces in the stomach/intestines, purgation is indicated, preferably with Da Chengqi Tang. If the abdomen is slightly full, with stool hard at the beginning and loose at the end, purgation is contraindicated. In Yangming disease, if cold affects the middle, causing inability to eat, difficulty urinating, and continuous sweating on the hands and feet, this suggests the impending formation of a Gujia (stubborn mass/accumulation), and the stool will likely be hard at the beginning and loose at the end. This is due to cold in the stomach and the failure to distinguish between water and grain.

Two to three days after contracting the disease, if the pulse is weak, without Taiyang or Shaoyang symptoms, and the patient is irritable with hardness below the heart, by the fourth or fifth day, even if they can eat, give small amounts of Xiao Chengqi Tang frequently to gently harmonize and bring slight relief. By the sixth day, administer one sheng of Chengqi Tang. If there is still no bowel movement, and urine output is low over six or seven days, even if they cannot eat, the stool is likely hard at the beginning and loose at the end, not yet fully hardened. Purgation will cause diarrhea. One must wait for free urination and confirmation of hard stool before purging, using Da Chengqi Tang.

[Commentary] Xu Shuwei stated: In Zhang Zhongjing's treatise, there are four instances mentioning stool that is hard at the beginning and loose at the end. The first two do not mention urination; the third mentions difficulty urinating, and the fourth mentions scanty urination. In the two cases not mentioning urination, the first is because the pathogenic heat in the stomach has not yet formed a heat-excess syndrome, and the second is due to deficiency, with irritant heat above and no dry feces in the stomach. Regarding the case of difficulty urinating, it is due to the failure to separate water and grain in the stomach. Regarding the case of scanty urination, it is because it is undetermined whether the stool is hard, so one must wait for urination to become free to verify. Thus, Zhang Zhongjing's method of assessing stool involves observing urination. If urine is clear, the disease is not in the interior; if diarrhea persists, promote urination; if urination is frequent and scanty, body fluids should return to the stomach, and the stool will naturally harden—all of which are verifiable. However, while free urination and confirmed hard stool indicate purgation is suitable, there are cases where urination is spontaneous and stool is hard, yet purgation is contraindicated. Why? If Yangming disease involves spontaneous sweating or post-sweating, with spontaneous urination, this indicates depletion of internal body fluids. Although the stool is hard, purgation is contraindicated. One should wait for the urge to defecate and use Honey Suppositories (Mi Jian Dao). This is not an interior excess syndrome, so purgation is inappropriate. Another Taiyang syndrome states: After vomiting or sweating, if there is mild irritability, frequent urination, and hard stool, give Xiao Chengqi Tang to harmonize. In these two cases, both involve hard stool and free urination after sweating, but the treatments differ. The latter case involves transmitted pathogenic factors, hence mild irritability; after sweating, vomiting, and purging, frequent urination leads to fluid loss and hard stool, indicating heat entering the interior, so Xiao Chengqi Tang is used to drain it. In the former case, spontaneous urination occurs without transmitted pathogens, hence no irritability; although the stool is hard, it is not an interior excess, merely dryness at the intestinal entrance, so only honey suppositories are applicable. Readers of Zhang Zhongjing's works should investigate this in detail.

Ke Qin stated: Gujia refers to stool that is hard at the beginning and loose at the end. Although the anus is constricted, the intestines are not completely dry. Loose stool is the sign of failing to separate water and grain. Interpreting Gujia otherwise is erroneous. The large and small intestines belong to the stomach. To determine the deficiency or excess of the stomach, one must examine the bowels and urine. Free urination indicates hard stool; difficulty urinating indicates stool hard at the beginning and loose at the end. Nowadays, people know that infrequent bowel movements, difficult defecation, and hard stool constitute Yangming disease. Do they also recognize that difficult urination, difficulty urinating, frequent/scanty urination, or anuria are also Yangming diseases?