应下失下，口燥舌干而渴，身反热减，四肢时厥，欲得近火壅被，此阳气伏也。
既下厥回，去炉减被，脉大而加数，舌上生津，不思水饮，此里邪去，郁阳暴伸也，宜柴胡
清燥汤去花粉、知母，加葛根，随其性而升泄之。此证类近白虎，但热渴既除，又非白虎所
宜也。
温疫下后二三日，或一二日，舌上复生苔刺，邪未尽也。再下之，苔刺虽未去，
已无锋芒而软，然热渴未除，更下之，热渴减，苔刺脱，日后更复热，又生苔刺，更宜下之
。余里周因之者，患疫月余，苔刺凡三换，计服大黄二十两，始得热不复作，其余脉证方退也
。所以凡下不以数计，有是证则投是药，医家见理不透，经历未到，中道生疑，往往遇
此证，反致耽搁。但其中有间日一下者，有应连下三四日者，有应连下二日间一日者，
其中宽缓之间，有应用柴胡清燥汤者，有应用犀角地黄汤者。至投承气，某日应多与，某日
应少与，其间不能得法，亦足以误事，此非可以言传，贵乎临时斟酌。
朱海畴者，年四十五岁，患疫得下证，四肢不举，身卧如塑，目闭口张，舌上苔刺，问其
所苦不能答，因问其子，两三日所服何药？云进承气汤三剂，每剂投大黄两许不效，更无他
策，惟待日而已，但不忍坐视，更祈一诊。余诊得脉尚有神，下证悉具，药浅病深也。先投
大黄一两五钱，目有时而小动，再投，舌刺无芒，口渐开能言。三剂舌苔少去，神思稍爽。
四日
服柴胡清燥汤，五日复生芒刺，烦热又加，再下之。七日又投承气养荣汤，热少退。八日仍
用大承气，肢体自能少动。计半月，共服大黄十二两而愈。又数日，始进糜粥，调理两月平
复。凡治千人，所遇此等，不过三四人而已，姑存案以备参酌耳。
如果应当使用下法（通过泻下通便来祛除体内实邪的治疗方法）而未能及时使用，患者会出现口燥、舌干且口渴的症状；身体反而发热减轻，四肢时常出现厥冷（手足逆冷），想要靠近火源并覆盖厚被，这是阳气伏郁在里的表现。
既然经过泻下治疗后，四肢厥冷消退，撤去炉火、减少盖被后，脉搏变得洪大且频率加快，舌上生出津液，不想喝水饮水，这是体内的邪气已去，郁结的阳气突然伸展所致，适宜使用柴胡清燥汤去掉天花粉、知母，加入葛根，顺应药性来升散宣泄邪热。这种证候接近白虎汤证，但既然热象和口渴已经消除，就不再适合使用白虎汤了。
温疫病患者在使用下法后的两三天内，或者一两天内，舌头上再次长出芒刺状的苔垢，说明邪气尚未清除干净。再次使用下法，虽然芒刺苔垢没有完全去除，但已经没有了尖锐的锋芒，变得柔软；然而热象和口渴仍未消除，继续用下法，热象和口渴会减轻，芒刺苔垢脱落，但日后又再次发热，重新长出芒刺苔垢，这时更应该继续使用下法。我有个叫周余里的病人因此病，患瘟疫一个多月，舌上的芒刺苔垢更换了三次，累计服用大黄二十两，才使得热象不再复发，其余的脉象和症状才逐渐消退。所以凡是使用下法，不能以次数来计算，只要有相应的证候就投用相应的药物。医生如果见理不透，经历不足，中途产生怀疑，往往遇到这种证候时，反而导致延误病情。但是其中也有隔一天用一次下法的，有应该连续使用下法三四天的，有应该连续使用下法两天中间间隔一天的，在这些宽缓的时间间隔中，有的应该使用柴胡清燥汤，有的应该使用犀角地黄汤。至于投用承气汤类方剂，哪一天应该多给剂量，哪一天应该少给剂量，如果不能掌握其中的方法，也足以误事，这并非可以通过言语传授就能掌握的，贵在根据当时情况灵活斟酌。
朱海畴，四十五岁，患瘟疫出现了可以使用下法的证候，四肢无法抬起，身体躺卧像塑像一样僵硬，眼睛闭着嘴巴张开，舌上有芒刺状苔垢，问他哪里不舒服不能回答，于是问他的儿子，这两三天吃了什么药？回答说服用了三剂承气汤，每剂投入约一两大黄，但没有效果，再也没有其他办法，只能等待时日而已，但不忍心坐着旁观，于是请求我再诊视一次。我诊察发现他的脉象还有神气，下法的证候全部具备，只是药力浅薄而病邪深重。先投入一两五钱大黄，眼睛有时会有轻微转动，再投药后，舌上的芒刺没有了尖锋，嘴巴渐渐能张开并能说话。服用三剂后，舌苔稍微退去，神志思维稍微清爽。第四天服用柴胡清燥汤，第五天芒刺又重新生长，烦热症状又加重，再次使用下法。第七天又投用承气养荣汤，热象稍微减退。第八天仍然使用大承气汤，肢体自然能够稍微活动。共计半个月，共服用大黄十二两而痊愈。又过了几天，才开始进食稀粥，调理两个月才完全康复。凡是我治疗的一千人中，遇到这种情况的不过三四人罢了，暂且保存这个医案以备参考斟酌。
If purgation (a treatment method using laxatives to remove excess pathogens from the body) should have been applied but was neglected, symptoms such as dry mouth, dry tongue, and thirst will occur. The body heat may paradoxically decrease, while the limbs experience periodic coldness (cold extremities), leading the patient to desire proximity to fire and thick coverings; this indicates the entrapment of Yang Qi within.
After purgation has been administered and the cold extremities resolve, if removing the heat source and reducing coverings results in a large and rapid pulse, moisture on the tongue, and a lack of desire for water or drinks, this signifies that the internal pathogens have been expelled and the constrained Yang Qi is suddenly extending. In such cases, Chaihu Qingzao Tang (Bupleurum Decoction to Clear Dryness) with Huafen (Trichosanthis Radix) and Zhimu (Anemarrhenae Rhizoma) removed, and Gegen (Puerariae Lobatae Radix) added, is appropriate to ascend and vent the pathogenic factors according to their nature. This syndrome resembles Baihu Tang syndrome; however, since the heat and thirst have already subsided, Baihu Tang is no longer suitable.
In patients with warm pestilence who have undergone purgation, if thorny moss-like coating reappears on the tongue within two or three days, or even one or two days after treatment, it indicates that the pathogens are not yet fully cleared. Purgation should be repeated. Although the thorny coating may persist, it will lose its sharpness and become soft. If heat and thirst remain unrelieved, further purgation should be administered. As heat and thirst diminish and the thorny coating sheds, fever may recur later with the reappearance of the thorny coating, necessitating continued purgation. My patient Zhou Yuli suffered from this condition for over a month due to pestilence. His tongue exhibited thorny coatings that changed three times, and he consumed a total of twenty taels of Dahuang (Rhei Radix et Rhizoma) before the fever ceased to recur, after which other pulse and symptom manifestations gradually receded. Therefore, when employing purgation, one should not count the number of doses; rather, administer the appropriate medicine for the presenting syndrome. Physicians who lack deep understanding or clinical experience often hesitate midway, causing delays in treating such cases. However, regimens vary: some require purgation every other day, some require consecutive purgation for three or four days, and others require consecutive purgation for two days followed by a one-day interval. During these intervals, Chaihu Qingzao Tang may be indicated in some cases, while Xijiao Dihuang Tang (Rhino Horn and Rehmannia Decoction) may be indicated in others. Regarding the administration of Chengqi Tang formulas, determining whether to increase or decrease the dosage on specific days requires skill that cannot be fully conveyed through words; it depends on flexible judgment at the time of treatment.
Zhu Haichou, aged forty-five, contracted pestilence and presented with indications for purgation. His limbs were immobile, his body lay rigid like a statue, his eyes were closed, and his mouth was open. A thorny coating appeared on his tongue. Unable to answer questions about his discomfort, his son reported that he had taken three doses of Chengqi Tang over two or three days, with approximately one tael of Dahuang per dose, without effect. With no other options, they could only wait, but unwilling to stand by idly, they sought another consultation. Upon examination, I found his pulse still possessed "Shen" (spirit/vitality), and all indications for purgation were present, suggesting the medication had been too mild for the depth of the disease. I initially administered one tael and five qian of Dahuang. Afterward, his eyes occasionally moved slightly. Upon subsequent administration, the sharpness of the thorny coating on his tongue disappeared, and his mouth gradually opened, allowing him to speak. After three doses, the tongue coating partially receded, and his mental clarity improved slightly. On the fourth day, he took Chaihu Qingzao Tang. On the fifth day, thorny spines reappeared, and irritability and heat intensified, requiring further purgation. On the seventh day, Chengqi Yangrong Tang (Chengqi Decoction to Nourish Ying) was administered, resulting in slight reduction of heat. On the eighth day, Da Chengqi Tang (Major Chengqi Decoction) was used again, enabling slight movement of the limbs. Over half a month, he consumed a total of twelve taels of Dahuang and recovered. Several days later, he resumed consuming congee and underwent conditioning for two months until full recovery. Among the thousand patients I treated, only three or four presented with such conditions. This case record is preserved here for reference.