【纲】仲景曰。太阴之为病。腹满而吐。食不下。自利益甚。时腹自痛。若下之。必胸下结硬。
【目】张元素曰。太阴本症。惟腹满自利而已。若邪迫于上。则吐而食不下也。邪迫于下。则
利甚而腹满也。上下相迫。必上下交乱。胃中空虚。法只可行温散之剂。其病自痊。若误下之。必
在下之邪去。而在上之邪陷。有不至于胸下结硬者哉。
魏荔彤曰。邪自外感。太阳先中之。邪自内传。太阴先受之。少阳之邪。既不能由半表而达表。
必由半里而入里。而里三阴之太阴。又为三阴之表。内经云。太阴主开是也。所以少阳之邪。传
经必先及太阴。亦不离内外表里之义而已矣。腹满而吐。食不下。自利腹痛。纯为太阴湿土。失镇
奠之令。故症全见于肠胃肚腹之间。本为三阳之邪。陷入阴经为患。法当升散其邪。复还阳分。若
以满痛为实邪而下之。则阳愈陷而下沉。阴愈凝而不散。胸下结硬。有似太阳之结胸而在下。有似
太阳之心下痞而又在上。胸下结硬。所以为太阴误下独见之症者如此。伤寒传经之邪。无论在太阳为
风因寒因。及遍历三阳。皆成热邪。复由阳而入阴。或误下误汗。又能变虚生寒。此病之变易莫测
也。惟其为热邪。所以作满而能吐。若寒邪。但胀满不食。必不能上逆为呕吐矣。自利而时腹痛。
利为挟热。时痛亦热邪。若寒邪。则痛隐隐无已时矣。所以知其确为热邪也。况凡病初得为寒。久
痛多热。亦理之常。太阳风寒之邪。传阳明时已变热矣。未有无所因而忽又变寒入三阴者。如谓入
三阴即为寒。何以有系在太阴之发黄也。发黄亦为寒邪耶。又何以三阴篇中用苦寒之剂。仲师立法。
不一而足。岂智不足耶。总由传经与直中之邪。分路不明。故见仲师立一温
散之法。便谓传经为寒邪。及见一恣用苦寒之法。便自己亦说不周全。遂含糊了事便罢。余不得不
于三阴之首条力争之。曰。直中有寒。传经悉热。（八字铁案）此二语确乎不易。再太阳结胸痞。
皆经误下而成。亦属风寒在表之邪。日久变热。遂成结聚。特风邪阳。聚于高分。寒邪阴。聚于
低分。然风因寒因。俱为已变热之邪无异也。所以陷胸泻心内。俱有苦寒之味。今此胸下结硬。又
岂能外陷胸泻心别求门路乎。或问。仲师意在温散。子言陷胸泻心。何也。曰。仲师温散。为太阴
未误下言。非为已下成胸下结硬者言也。亦如太阳未误下。用辛温。已误下。用苦寒也。三阳为表。
三阴为里。固矣。三阳有三阳之表里。三阴有三阴之表里。岂可一阳而尽表之理。一阴而尽阴之
道乎。此乃伤寒中之大关键也。
【纲】仲景曰。寒实结胸。无热症者。与三白小陷胸汤。为散亦可服。
【目】柯琴曰。太阳表热未除而反下之。热邪与寒水相结。成热实结胸。太阴腹满时痛而反下
之。寒邪与寒药相结。成寒实结胸也。无热症者。不四肢烦疼也。
[Outline] Zhang Zhongjing said: The main manifestations of Taiyin disease are abdominal fullness, vomiting, difficulty in swallowing food, diarrhea that gradually worsens, and spontaneous abdominal pain occurring from time to time. If purgation is mistakenly applied, it will inevitably lead to hardness and obstruction below the chest.
[Commentary] Zhang Yuansu said: The primary symptoms of Taiyin disease are merely abdominal fullness and diarrhea. If pathogenic factors press upon the upper part, vomiting and inability to eat will occur; if they press upon the lower part, severe diarrhea and abdominal fullness will result. When pathogens in the upper and lower parts mutually oppress each other, the qi mechanism in both regions must become chaotic. At this stage, the stomach is empty. According to medical principles, only warming and dispersing agents should be used, and the disease will heal spontaneously. If purgation is mistakenly applied, the pathogens in the lower part may be expelled, but the pathogens in the upper part will sink inward. Would this not inevitably lead to hardness and obstruction below the chest?
Wei Litong said: Pathogens acquired externally first affect the Taiyang channel; pathogens transmitted internally first affect the Taiyin channel. Shaoyang pathogens, since they cannot reach the exterior via the half-exterior/half-interior level, must enter the interior via the half-interior. Among the three Yin channels, Taiyin serves as the exterior of the three Yin. As stated in the *Neijing* (Inner Canon), "Taiyin governs opening." Therefore, Shaoyang pathogens transmitting through the channels must first involve Taiyin, which aligns with the principles of interior/exterior and surface/depth. Abdominal fullness, vomiting, inability to eat, diarrhea, and abdominal pain are purely due to the failure of Taiyin damp-earth to maintain its stabilizing function. Thus, symptoms manifest entirely in the intestines, stomach, and abdomen. This originates from pathogens of the three Yang channels sinking into the Yin channels to cause pathology. The treatment method should be to ascend and disperse the pathogens, restoring them to the Yang level. If fullness and pain are mistaken for excess pathogens and treated with purgation, Yang qi will sink further, and Yin qi will become more stagnant and undispersed. Hardness and obstruction below the chest resemble the chest binding of Taiyang disease but located lower, and resemble the epigastric stuffiness of Taiyang disease but located higher. This is why hardness and obstruction below the chest is a unique symptom appearing after mistaken purgation in Taiyin disease. Regarding pathogens transmitted through the channels in cold damage diseases, whether presenting as wind or cold at the Taiyang stage, or traversing the three Yang channels, they all transform into heat pathogens. They then transmit from Yang to Yin. Alternatively, mistaken purgation or sweating can cause deficiency and generate cold. This unpredictability characterizes the changes in disease. Precisely because it is a heat pathogen, it causes fullness and vomiting. If it were a cold pathogen, there would only be distension and anorexia, absolutely no upward reversal causing vomiting. Diarrhea accompanied by intermittent abdominal pain indicates diarrhea with heat; intermittent pain also indicates heat pathogens. If it were a cold pathogen, the pain would be dull, lingering, and ceaseless. Therefore, we can confirm it is a heat pathogen. Moreover, it is a common principle that diseases initially present as cold, but prolonged pain often transforms into heat. When wind-cold pathogens of Taiyang transmit to Yangming, they have already transformed into heat. There is no case where pathogens suddenly transform into cold and enter the three Yin channels without cause. If entering the three Yin always meant cold, why does "lingering in Taiyin" cause jaundice? Is jaundice caused by cold pathogens? Why are bitter-cold formulas used in the chapter on the three Yin channels? Zhang Zhongjing established various methods; was his wisdom insufficient? It is simply because the distinction between transmitted pathogens and directly invading pathogens was unclear. Upon seeing Zhang Zhongjing establish a warming and dispersing method, one might wrongly conclude that transmitted pathogens are cold. Upon seeing a liberal use of bitter-cold methods, one might find oneself unable to explain fully and thus gloss over it ambiguously. I could not help but vigorously argue at the beginning of the three Yin chapter, stating: Direct invasion involves cold; transmission involves heat. (This is an unchangeable iron-clad case.) These two statements are indeed indisputable. Furthermore, chest binding and epigastric stuffiness in Taiyang disease are all caused by mistaken purgation. They belong to wind-cold pathogens in the exterior that transform into heat over time, leading to aggregation. Wind pathogens are Yang and aggregate in high positions (upper); cold pathogens are Yin and aggregate in low positions (lower). However, whether originating from wind or cold, they are essentially heat-transformed pathogens with no difference. Therefore, Xiaoxin Tang (Minor Chest-Draining Decoction) and Xixin Tang (Epigastric-Purgating Decoction) contain bitter-cold ingredients. Now, regarding this hardness and obstruction below the chest, how could it possibly deviate from Xiaoxin Tang and Xixin Tang to seek another approach? Someone asked: Zhang Zhongjing intended warming and dispersing, yet you speak of Xiaoxin Tang and Xixin Tang. Why? I replied: Zhang Zhongjing's warming and dispersing method applies to Taiyin disease before mistaken purgation, not to cases where hardness and obstruction below the chest have already formed due to purgation. This is analogous to using acrid-warm herbs for Taiyang disease before mistaken purgation, and bitter-cold herbs after mistaken purgation. It is true that the three Yang channels are exterior and the three Yin channels are interior. However, the three Yang channels have their own interior/exterior distinctions, and the three Yin channels have their own interior/exterior distinctions. How can one claim that a single Yang channel is entirely exterior, or a single Yin channel is entirely interior? This is a critical point in the study of cold damage diseases.
[Outline] Zhang Zhongjing said: For cold-excess chest binding characterized by the absence of heat symptoms, Sanbai Xiaoxin Tang (Three-White Minor Chest-Draining Decoction) should be administered. It may also be taken as a powder.
[Commentary] Ke Qin said: If the exterior heat of Taiyang is not resolved and purgation is mistakenly applied, heat pathogens bind with cold water, forming heat-excess chest binding. If abdominal fullness and intermittent pain of Taiyin are not addressed correctly and purgation is mistakenly applied, cold pathogens bind with cold-natured drugs, forming cold-excess chest binding. "Absence of heat symptoms" refers to the lack of vexatious pain in the four limbs.