仲景伤寒论云。寒邪外伤。传而入里。里者。入胃是也。邪气入胃。则变而为热。胃中之气郁
滞。糟粕秘结。壅而为实。实则泻之。人所共知。如缓急轻重之剂。则临时消息焉。若不恶寒反恶
热。谵语烦渴。腹满而喘。手足 然汗出者。急下之。宜大承气汤。如邪气入深。恐有燥屎。欲知
之法。与小承气汤试之。若腹中转失气者。有燥屎也。乃可攻之。不转失气者。必初硬而后溏。尚
未可攻。攻之则腹满不能食。若腹大满不通者。亦以小承气汤微和其胃气。勿令大泄也。如发汗后
不恶寒但热者。胃实也。当和其胃气。调胃承气汤主之。成无己云。大热结实者。大承气。小热微
结者小承气。以热不甚大。故于大承气汤内去芒硝又以结不至坚。故不减浓朴、枳实也。如不至大
坚满。邪气盛而须攻下者。亦未可投大承气汤。必以轻缓之剂攻之、于大承气汤中去浓朴、枳实、
加甘草。乃轻缓之剂也。若大承气证。反用调胃承气汤治之。则邪气不散。小承气汤证。反用大承
气汤下之。则过伤正气。而腹满不能食。故有勿大泄之戒。此仲景所以分而治之。未尝越圣人之制
度。后之学人。以此三药合而为一。且云通治三药之证。及无问伤寒杂病内外一切所伤。一概治之。
若根据此说。与仲景之方。甚相违背。又失轩岐缓急之旨。红紫乱朱。迷惑众听。一唱百和。使病者
暗受其弊。将何诉哉。有公心审是非者。于内经仲景方内求责。使药证相对。以圣贤之心为心。则
方之真伪。
自可得而知矣。
张仲景在《伤寒论》中说：寒邪从体表侵入，传入体内。所谓“里”，指的是进入胃腑。邪气进入胃中，就会转化为热邪。胃中的气机郁滞不畅，糟粕（粪便）秘结不通，壅塞而形成实证。对于实证应当采用泻法，这是人们所共知的道理。至于使用缓急轻重不同的方剂，则需根据病情的具体情况临时斟酌决定。
如果患者不恶寒反而怕热，出现胡言乱语、心烦口渴、腹部胀满且喘息、手足濈然汗出等症状，应当紧急攻下，适宜使用大承气汤。
如果邪气深入体内，担心有燥屎内结，想要确认是否有燥屎的方法，可以先给予小承气汤进行试探。如果服药后腹中转动排气（放屁），说明有燥屎存在，才可以进行攻下治疗；如果不排气，说明大便一定是开头硬后面稀溏，此时还不可以攻下。如果强行攻下，会导致腹部胀满、不能进食。
如果腹部显著胀满且大便不通的情况，也只用小承气汤轻微调和胃气，不要让它造成剧烈腹泻。
如果在发汗之后，患者不再恶寒只是发热，这是胃实证的体现，应当调和胃气，以调胃承气汤为主治方剂。
成无己说：大热且结实严重的，用大承气汤；小热且微结的，用小承气汤。因为热势不是特别盛大，所以在大承气汤中去掉了芒硝；又因为结滞不至于坚硬，所以不减去厚朴和枳实。
如果病情不到大坚满的程度，但邪气旺盛需要攻下的，也不能投用大承气汤。必须使用轻缓的方剂来攻下，即在大承气汤中去掉厚朴、枳实，加入甘草，这才是轻缓的方剂。
如果是大承气汤的适应证，却反用调胃承气汤治疗，那么邪气就不能消散；如果是小承气汤的适应证，却反用大承气汤攻下，则会过度损伤正气，导致腹部胀满、不能进食。因此有“不要造成剧烈腹泻”的告诫。这就是张仲景之所以分别治疗的原因，从未超越圣人的法度。
后世学习的人，将这三首方剂的药物合而为一，并且声称可以通治这三首方剂所对应的证候，以及不问是伤寒还是杂病、内伤还是外感的一切损伤，一概用此方治疗。如果依据这种说法，与张仲景的原方精神非常违背，又失去了黄帝内经中关于用药缓急的宗旨。这就好比红紫混淆了正朱色，迷惑了大众的听闻，一人倡导百人附和，使病患者暗中受到损害，又能向谁申诉呢？
如果有公正之心、能审辨是非的人，应当在《内经》和张仲景的方剂中寻求依据，使药物与证候相对，以圣贤的心意为心意，那么方剂的真伪自然就可以知道了。
Zhang Zhongjing stated in the *Treatise on Cold Pathogenic Diseases* (*Shanghan Lun*): When cold pathogen (*Han Xie*) invades from the exterior and transmits inward, "inward" refers to entering the Stomach (*Wei*). Once the pathogen enters the Stomach, it transforms into heat. The Qi (*vital energy*) within the Stomach becomes stagnant and obstructed, causing waste matter (feces) to become constipated and accumulated, resulting in an Excess syndrome (*Xu Shi*). For Excess syndromes, purgation is indicated, a principle well known to all. However, the choice of agents with varying degrees of urgency and strength should be decided temporarily based on the specific situation.
If the patient does not feel aversion to cold but instead feels aversion to heat, accompanied by delirious speech (*Zhan Yu*), irritability, thirst, abdominal fullness, and panting, along with continuous sweating on the hands and feet (*Ji Ji Han Chu*), urgent purgation is required. Da Cheng Qi Tang (Major Order the Qi Decoction) is appropriate.
If the pathogen has penetrated deeply and there is concern about dry fecal matter (*Zao Shi*), the method to verify its presence is to administer Xiao Cheng Qi Tang (Minor Order the Qi Decoction) as a test. If gas moves in the abdomen after administration (flatus), it indicates the presence of dry fecal matter, and purgation may then proceed. If no flatus occurs, it implies that the stool is likely hard at the beginning and loose at the end; purgation is not yet indicated. Purgation at this stage would lead to abdominal fullness and inability to eat.
In cases of significant abdominal fullness and obstruction without defecation, Xiao Cheng Qi Tang should also be used to gently harmonize the Stomach Qi, avoiding severe diarrhea.
After sweating therapy, if the patient no longer feels aversion to cold but only exhibits heat, this indicates a Stomach Excess condition. The Stomach Qi should be harmonized, and Tiao Wei Cheng Qi Tang (Regulate the Stomach Order the Qi Decoction) should be administered.
Cheng Wuji stated: For severe heat with solid accumulation, Da Cheng Qi Tang is used; for mild heat with slight accumulation, Xiao Cheng Qi Tang is used. Because the heat is not excessively intense, Mang Xiao (Natrii Sulfas) is removed from Da Cheng Qi Tang. Furthermore, because the accumulation is not extremely hard, Hou Po (Magnoliae Officinalis Cortex) and Zhi Shi (Aurantii Fructus Immaturus) are not reduced in dosage.
If the condition does not reach the state of severe hardness and fullness, but the pathogen is abundant and requires purgation, Da Cheng Qi Tang should not be administered. Instead, a milder agent must be used for purgation. This involves removing Hou Po and Zhi Shi from Da Cheng Qi Tang and adding Gan Cao (Glycyrrhizae Radix et Rhizoma), creating a milder formula.
If the indications match Da Cheng Qi Tang but Tiao Wei Cheng Qi Tang is mistakenly used, the pathogen will not dissipate. Conversely, if the indications match Xiao Cheng Qi Tang but Da Cheng Qi Tang is used for purgation, it will excessively damage the healthy Qi (*Zheng Qi*), leading to abdominal fullness and inability to eat. Hence, the warning against causing severe diarrhea exists. This is why Zhang Zhongjing treated these conditions separately, never deviating from the principles established by the Sages.
Later scholars have combined the ingredients of these three formulas into one, claiming they can treat all syndromes indicated by these three formulas, as well as all injuries regardless of whether they are Cold Damage (*Shang Han*), miscellaneous diseases, internal, or external causes. Following such a theory contradicts the original prescriptions of Zhang Zhongjing and loses the essence of urgency and moderation found in the *Inner Canon of the Yellow Emperor* (*Huangdi Neijing*). This is akin to red and purple confusing the true vermilion, misleading the public. One voice is followed by a hundred, causing patients to suffer silently, leaving them with no recourse for complaint.
Those with a sense of justice and the ability to discern right from wrong should seek answers within the *Neijing* and Zhang Zhongjing’s formulas, ensuring that the herbs correspond precisely to the syndromes. By adopting the mindset of the sages, the authenticity and validity of the formulas will naturally become clear.