汗，是伤寒之阴邪不得散，而两阳之热邪不得舒，相搏于心下而成痞也。法当佐以附子，炮用而别煮，以温其
积寒，三物生用而取汁。欲急于除热，寒热各制而合服之。是又于偶方中用反佐之奇法也。夫结热不速去，必成胃家之
燥实；心下痞不散，必转成为大结胸。此二方用麻沸汤之意欤？仲景泻心无定法，正气夺则为虚痞，杂用甘补、
辛散、苦泄、寒温之品以和之；邪气盛则为实痞，用大寒、大热、大苦、大辛之味以下之。和有轻重之分，下
有寒热之别，同名泻心，而命剂不同如此。然五方中诸药味数分两，各有进退加减，独黄连定而不移者，以其
苦先入心，中空外坚，能疏通诸药之寒热，故为泻心之主剂。
旋复代赭汤∶
旋复 代赭 人参 甘草 半夏 生姜 大枣
伤寒发汗，若吐若下，表解后，心下痞硬，噫气不除者，此心气大虚，余邪结于心下，心气不得降而然也。
心为君主，寒为贼邪。表寒虽解而火不得位，故使闭塞不通，而心下痞硬；君主不安，故噫气不除耳。此方乃泻
心之变剂，以心虚不可复泻心，故去芩、连、干姜辈苦寒辛热之品。心为太阳，通于夏气。旋复花开于夏，咸
能补心而软痞硬；半夏根成于夏，辛能散结气而止噫。二味得夏气之全，故用之以通心气。心本苦缓，此为贼
邪伤残之后，而反苦急，故加甘草以缓之；心本欲收，今因余邪留结，而反欲散，故倍生姜以散之。虚气上逆
，非得金石之重为之镇坠，则痞硬不能遽消，而噫气无能顿止。代赭秉南方之赤色，入通于心，坚可除痞，重
可除噫，用以为佐，急治其标也。人参、大枣，补虚于余邪未平之时，预治其本也。扶正驱邪，神自安。若用
芩、连以泻心，能保微阳之不灭哉？旋复、半夏作汤，调代赭末，治顽痰结于胸膈，或涎沫上涌者最佳。挟虚
者加人参甚效。
干姜黄连黄芩人参汤∶
治伤寒吐下后，食入口即吐。此寒邪格热于上焦也，虽不痞硬而病本于心，故用泻心之半。干姜以散上焦
之寒，芩、连以清心下之热，人参以通格逆之气，而调其寒热以至和平。去生姜、半夏者，胃虚不堪辛散；不
用甘草、大枣者，呕不宜甘也。凡呕家夹热者，不利于香砂桔半，服此方而晏如。妄汗后，水药不得入口，是
为水逆；妄吐下后，食入口即吐，是为食格。此肺气胃气受伤之别也。入口即吐，不使少留，乃火炎上之象，
故苦寒倍于辛热。不名泻心者，以泻心汤专为痞硬之法耳。要知寒热相结于心下，而成痞硬，寒热相阻于心下，
而成格逆，源同而流异也。
赤石脂禹余粮汤∶
下后下利不止，与理中汤而痢益甚者，是胃关不固，下焦虚脱也。夫甘、姜、参、术，可以补中宫大气之
虚，而不足以固大肠脂膏之脱。故利在下焦者，概不得以理中之理收功矣。夫大肠之不固，仍责在胃；关门之
不闭，仍责在脾。土虚不能制水，仍当补土。然芳草之气，禀甲乙之化，土之所畏，必择夫禀戊土之化者，以
培土而制水，乃克有成。石者，土之刚也。二石皆土之精气所结，味甘归脾，气冲和而性凝静，用以固堤防而
平水土，其功胜于草木耳。且石脂色赤入丙，助火以生土，余粮色黄入戊，实胃而涩肠，用以治下焦之标，实
以培中宫之本也。此症土虚而火不虚，故不宜于姜、附。本条云∶“复利不止者，当利其小便。”可知与桃花
汤异局矣。凡下焦虚脱者，以二物为本，参汤调服最效。
抵当汤丸∶
水蛭 大黄 虻虫 桃仁
太阳病六七日，而表症仍在，阳气重可知。脉当大而反微，当浮而反沉。沉为在里，当作结胸之症，反不
结胸，是病不在上焦；诸微无阳，而其人反发狂者，是病不在气分矣。凡阳病者，上行极而下，是热在下焦可知。
下焦不治，少腹硬满，是热结于膀胱，当有癃闭之患。而小便反利者，是上焦肺家之气化行，经络之营气不利
也。人知内热则小便不通，此热结膀胱，而小便反利，当知小便由肺气矣。凡阳盛者阴必虚，气胜者血必病。
瘀热内结于膀胱，营血必外溢于经络。营气伤，故脉微而沉；瘀血蓄，故少腹硬满。血瘀不行，心不得主，肝无
所藏，神魂不安，故发狂，或身黄而脉沉结者，皆由营气不舒故也。只以小便之自利决之，则病在血分而不谬矣。
夫瘀血不去，则新血不生，营气不流，则五脏不通而死可立待。岐伯曰∶“血清气涩，疾泻之，则气竭焉；血浊
气涩，疾泻之，则经可通也。”非得至峻之剂，不足以抵其巢穴，而当此重任矣。水蛭，虫之巧于饮血者也；虻，
飞虫之猛于吮血者也。兹取水陆之善取血者攻之，同气相求耳。更佐桃仁之推陈致新，大黄之苦寒以荡涤邪热，
名之曰抵当者，谓直抵其当攻之所也。若虽热而未狂，小腹满而未硬，宜小其制，为丸以缓治之。若外证已解，
少腹结急而满，人如狂者，是转属阳明也，用桃仁、桂枝于调
胃承气汤中以微利之，胃和则愈矣。或问血得热则行，此何以反结？膀胱热则小便不通，此何以反利乎？答曰∶
冲脉为血海，而位居少腹之上，膀胱居小腹之极底。膀胱热而血多，则血自下而不蓄；膀胱热而血少，则血凝
而结于少腹矣。水入于胃，上输脾肺，下输膀胱，膀胱为州都之官，全藉脾肺气化而津液得出。此热在下焦，
上中二焦之气化不病，故小便自利也。膀胱不利为癃，由太阴之不固∶不约为遗溺，由太阴之不摄。仲景制大
青龙、大柴胡、白虎汤，治三阳无形之热结。三承气之热实，是糟粕为患，桃仁、抵当之实结，是蓄血为眚，
在有形中又有气血之分也。凡仲景用硝、黄，是荡热除秽，不是除血。后人专以气分血分对讲，误认糟粕为血，
竟推大黄为血分药，不知大黄之芳香，所以开脾气而去腐秽，故方名承气耳。若不加桃仁，岂能破血？非加蛭、
虻，何以攻坚？是血剂中又分轻重也。凡 瘕不散；久而成形者，皆蓄血所致。今人不求其属而治之，反用三
棱等气分之药，重伤元气，元气日衰，邪气易结。盖谓糟粕因气行而除，瘀血因气伤而反坚也。明知此理，则
用抵当丸，得治 瘕及追虫攻毒之效。
按∶水蛭赋体最柔，秉性最险，暗窃人血而人不知。若饮水而误吞之，留恋胃中，消耗血液，腹中或痛或
不痛，令人黄瘦而死。观牛肚中有此者必瘦，可类推矣。虻虫之体，能高飞而远举，专吮牛血，其形气猛于苍
蝇。观苍蝇取人血汗最痛，误食入胃，即刻腹痛，必泻出而后止。可知飞虫为阳属，专取营分之血，不肯停留
胃中，与昆虫之阴毒不同也。仲景取虻、蛭同用，使蛭亦不得停留胃中，且更有大黄以荡涤之，毒物与蓄血俱
去，而无遗祸。然二物以毒攻毒者也，若非邪气固结，元气不虚者，二物不可轻用矣。
上共四十六方，其桂枝加葛根、葛根加半夏等，最为易晓，故不具论。如四逆、真武等剂，乃太阳所借用，
其方论各归本位，经论列于后。
汗法运用不当，导致伤寒的阴邪无法发散，同时两阳（指太阳与阳明）的热邪也无法舒展，二者在心下相互搏结而形成痞证。治疗法则应当辅助使用附子，将附子炮制后单独煎煮，以温散其积聚的寒邪；其余三味药生用取汁。为了急于清除热邪，使寒药与热药分别制备后混合服用。这又是于偶方之中运用反佐的奇法。如果结聚的热邪不迅速去除，必然形成胃家燥实之证；心下的痞塞如果不消散，必然转变为大结胸证。这两张方剂使用麻沸汤（滚开水）浸泡的意义大概就在这里吧？
张仲景治疗泻心证没有固定的方法，如果正气亏虚则成为虚痞，杂用甘补、辛散、苦泄、寒温等药物来调和它；如果邪气盛实则成为实痞，使用大寒、大热、大苦、大辛的药物来攻下它。调和有轻重的区别，攻下有寒热的不同，虽然都叫“泻心”，但组方用药却如此不同。然而在这五首泻心方中，各药物的种类和剂量各有进退加减，唯独黄连固定不变，因为苦味先入心，黄连中空外坚，能够疏通诸药的寒热属性，所以作为泻心方的主药。
旋复代赭汤：
组成：旋复花、代赭石、人参、甘草、半夏、生姜、大枣。
伤寒经过发汗，或者呕吐、攻下之后，表证已解，但出现心下痞硬，嗳气不止的症状，这是因为心气大虚，残余的邪气结聚在心下，导致心气不能下降所致。
心为君主之官，寒为贼邪。表寒虽然解除，但心火不得其位，导致闭塞不通，所以心下痞硬；君主不安宁，所以嗳气不止。此方是泻心汤的变方，因为心气虚弱不能再直接泻心，所以去掉了黄芩、黄连、干姜等苦寒辛热的药物。心对应太阳经，通应于夏气。旋复花在夏季开花，咸味能补心并软化痞硬；半夏在夏季成熟，辛味能散结气并止住嗳气。这两味药得夏气之全，所以用来通达心气。心本应苦缓，但在遭受贼邪伤残之后，反而变得急迫，所以加入甘草来缓和它；心本欲收敛，现在因为余邪留结，反而想要疏散，所以加倍使用生姜来疏散它。虚气上逆，如果不是用金石类的重镇药物来镇压坠降，那么痞硬就不能迅速消除，嗳气也不能立刻停止。代赭石秉承南方的赤色，入通于心，质地坚硬可以消除痞硬，质量沉重可以消除嗳气，用作佐药，是为了急治其标。人参、大枣，在余邪未平之时补益虚损，是为了预治其本。扶助正气驱除邪气，神志自然安宁。如果使用黄芩、黄连来泻心，怎么能保护微弱的阳气不灭呢？旋复花、半夏煎汤，调服代赭石末，治疗顽痰结于胸膈，或者涎沫上涌的情况最佳。兼有虚证的加入人参非常有效。
干姜黄连黄芩人参汤：
主治伤寒经过吐下之后，食物入口即吐。这是寒邪格拒热邪于上焦的缘故，虽然没有痞硬，但病本在心，所以使用泻心汤的一半剂量。干姜用来散上焦的寒邪，黄芩、黄连用来清心下的热邪，人参用来通达格逆之气，从而调和寒热达到平和。去掉生姜、半夏，是因为胃虚不堪受辛散之品；不用甘草、大枣，是因为呕吐不宜用甘味药。凡是呕吐夹有热邪的患者，不适合使用香砂桔半类方剂，服用此方则安然无恙。误用汗法后，水药不得入口，这叫水逆；误用吐下法后，食入口即吐，这叫食格。这是肺气与胃气受伤的区别。食物入口即吐，不让其在体内稍作停留，这是火炎上的象，所以苦寒药多于辛热药。不命名为泻心汤，是因为泻心汤专门针对痞硬证。要知道，寒热相结于心下，形成痞硬；寒热相阻于心下，形成格逆，源头相同而表现各异。
赤石脂禹余粮汤：
攻下之后下利不止，服用理中汤后痢疾反而加重，这是胃关不固，下焦虚脱的表现。夫甘草、干姜、人参、白术，可以补益中宫大气之虚，但不足以固摄大肠脂膏之脱漏。所以利在下焦的病证，一概不能用理中汤的道理来收功。大肠的不固，责任仍在胃；关门的不闭，责任仍在脾。土虚不能制水，仍应当补土。然而芳草类药物，禀受甲乙木气之化，是土所畏惧的，必须选择禀受戊土气化者，来培土制水，才能成功。石头，是土的刚强部分。这两种石药都是土的精气凝结而成，味甘归脾，气冲和而性凝静，用来巩固堤防而平水土，其功效胜过草木。而且石脂色赤入丙火，助火以生土；余粮色黄入戊土，充实胃气而涩肠，用来治疗下焦之标，实际上是培补中宫之本。此症是土虚而火不虚，所以不适合用干姜、附子。本条原文说：“复利不止者，当利其小便。”可知这与桃花汤的治疗格局不同。凡属下焦虚脱者，以这两味药为本，用人参汤调服效果最好。
抵当汤丸：
组成：水蛭、大黄、虻虫、桃仁。
太阳病六七日，表证仍在，说明阳气郁重可知。脉应当大而反微，应当浮而反沉。沉表示病在里，应当出现结胸症状，反而不结胸，说明病不在上焦；诸微无阳，而其人反而发狂，说明病不在气分。凡是阳病，上行至极则下行，说明热在下焦可知。下焦不治，少腹硬满，说明热结于膀胱，应当有癃闭（小便不通）的隐患。而小便反而通利的，说明上焦肺的气化功能正常，经络中的营气不利。人们只知道内热会导致小便不通，这里热结膀胱而小便反利，应当知道小便的通利取决于肺气。凡是阳盛者阴必虚，气胜者血必病。瘀热内结于膀胱，营血必然外溢于经络。营气受伤，所以脉微而沉；瘀血蓄积，所以少腹硬满。血瘀不行，心不得主宰，肝无所藏，神魂不安，所以发狂，或者身黄而脉沉结的，都是由营气不舒所致。只要根据小便自利这一症状来判断，就知道病在血分而不谬误了。
如果瘀血不去，新血就无法生成，营气不流通，五脏不通而死期可待。岐伯说：“血清气涩，疾泻之，则气竭焉；血浊气涩，疾泻之，则经可通也。”非得至峻猛的药剂，不足以直捣其巢穴，担当此重任。水蛭，是昆虫中善于饮血的；虻，是飞虫中猛烈于吮血的。这里取水陆两种善于取血的动物来攻逐瘀血，是同气相求。更佐以桃仁推陈致新，大黄苦寒以荡涤邪热，命名为抵当，意思是直抵应当攻逐的地方。如果虽然有热但未发狂，小腹满而未硬，宜减小剂量，制成丸药以缓治之。如果外证已解，少腹结急而满，人如狂状，这是转属阳明病，用桃仁、桂枝加入调胃承气汤中以轻微通下，胃气和则痊愈。
有人问：血得热则行，为什么这里反而凝结？膀胱热则小便不通，为什么这里反而通利？回答说：冲脉为血海，位居少腹之上，膀胱居小腹之极底。膀胱热而血多，则血自下而不蓄积；膀胱热而血少，则血凝而结于少腹。水进入胃，上输脾肺，下输膀胱，膀胱为州都之官，全赖脾肺气化而津液得出。此热在下焦，上中二焦的气化未受影响，所以小便自利。膀胱不利为癃，是由于太阴不固；不约为遗溺，是由于太阴不摄。张仲景制定大青龙、大柴胡、白虎汤，治疗三阳无形之热结。三承气汤治疗的热实，是糟粕为患；桃仁承气、抵当汤治疗的实结，是蓄血为害，在有形之中又有气血之分。凡是张仲景使用硝石、大黄，是荡热除秽，不是除血。后人专以气分血分相对讲，误认糟粕为血，竟推崇大黄为血分药，不知道大黄的芳香，是用来开脾气而去腐秽的，所以方名承气。如果不加桃仁，怎能破血？不加蛭、虻，何以攻坚？这是血剂中又分轻重。凡是瘕块不散，久而成形的，都是蓄血所致。今人不探究其归属而治疗，反而使用三棱等气分之药，重伤元气，元气日渐衰败，邪气容易结聚。可以说糟粕因气行而除，瘀血因气伤而反坚。明知此理，则使用抵当丸，可得治疗瘕块及追虫攻毒的效果。
按语：水蛭赋体最柔，秉性最险，暗中窃取人的血液而人不知晓。如果饮水时误吞，留恋胃中，消耗血液，腹中或痛或不痛，令人黄瘦而死。观察牛肚中有此虫者必定消瘦，可类推其他情况。虻虫的形体，能高飞远举，专吮牛血，其形气比苍蝇猛烈。观察苍蝇取人血汗最痛，误食入胃，即刻腹痛，必须泻出后才停止。可知飞虫为阳属，专取营分之血，不肯停留在胃中，与昆虫的阴毒不同。张仲景取虻、蛭同用，使蛭也不得停留在胃中，且更有大黄以荡涤之，毒物与蓄血俱去，而无遗留祸患。然而这两味药是以毒攻毒，如果不是邪气固结，元气不虚者，这两味药不可轻用。
以上共四十六方，其中桂枝加葛根、葛根加半夏等，最为易懂，故不详细论述。如四逆、真武等方剂，乃太阳病所借用，其方论各归本位，经文论述列于后。
Perspiration therapy, when misapplied, causes the yin pathogenic factor of cold damage to fail to dissipate, while the heat pathogenic factors of the two yang (referring to the Taiyang and Yangming channels) fail to expand. They contend with each other at the epigastrium, forming a *pi* syndrome (fullness and obstruction). The treatment principle should involve assisting with *Fuzi* (Prepared Aconite Root), which is processed and decocted separately to warm and disperse the accumulated cold; the other three herbs are used raw to extract their juice. This approach aims to urgently clear the heat by preparing the cold and hot medicines separately and then mixing them for administration. This represents a clever method of counter-assistance (*fan zuo*) employed within an even-numbered formula. If the knotted heat is not rapidly eliminated, it will inevitably develop into dry excess in the stomach (*wei jia zao shi*); if the epigastric fullness does not dissipate, it will inevitably transform into a major *jie xiong* syndrome (chest binding). Is this the meaning behind using boiling water (*ma fei tang*) to soak these two formulas?
Zhang Zhongjing has no fixed method for treating *xie xin* (draining the heart/epigastrium). If healthy qi is depleted, it becomes deficiency-type *pi*; various sweet-tonifying, acrid-dispersing, bitter-draining, and cold-warming herbs are mixed to harmonize it. If pathogenic qi is abundant, it becomes excess-type *pi*; strongly cold, strongly hot, strongly bitter, and strongly acrid flavors are used to purge it. Harmonization has degrees of lightness and heaviness, while purging has distinctions of cold and heat. Although both are named "draining the heart," the composition and dosage differ so greatly. However, among these five *xie xin* formulas, the types and dosages of various herbs have their own advances and reductions, except for *Huanglian* (Coptis Rhizome), which remains fixed. This is because the bitter flavor enters the heart first; *Huanglian* is hollow inside and firm outside, capable of unblocking the cold and heat properties of other herbs, thus serving as the chief agent for draining the heart.
*Xuanfu Daizhe Tang* (Inula and Hematitum Decoction):
Ingredients: *Xuanfuhua* (Inula Flower), *Daizheshi* (Hematitum), *Renshen* (Ginseng Radix), *Gancao* (Licorice Root), *Banxia* (Pinellia Tuber), *Shengjiang* (Fresh Ginger Rhizome), *Dazao* (Jujube Fruit).
After cold damage is treated with perspiration, vomiting, or purgation, once the exterior syndrome resolves, but epigastric hardness and persistent belching occur, this is due to severe deficiency of heart qi, with residual pathogenic factors knotting at the epigastrium, preventing heart qi from descending.
The Heart is the Sovereign Lord; cold is a thief pathogen. Although the exterior cold has resolved, the fire of the Heart loses its proper position, causing blockage and resulting in epigastric hardness; because the Sovereign Lord is unsettled, belching persists. This formula is a variation of the *Xie Xin* formulas. Since heart qi is deficient and cannot be directly drained again, the bitter-cold and acrid-hot herbs like *Qinh* (Scutellaria Root), *Lian* (Coptis Rhizome), and *Ganjiang* (Dried Ginger Rhizome) are removed. The Heart corresponds to the Taiyang channel and connects with the Qi of Summer. *Xuanfuhua* blooms in summer; its salty flavor can tonify the heart and soften hardness. *Banxia* matures in summer; its acrid flavor can disperse knotting qi and stop belching. These two herbs fully acquire the Qi of Summer, so they are used to unblock heart qi. The Heart naturally tends toward relaxation, but after injury by the thief pathogen, it becomes tense; therefore, *Gancao* is added to relax it. The Heart naturally tends toward contraction, but now, due to residual pathogenic retention, it needs dispersion; therefore, *Shengjiang* is doubled to disperse it. For ascending rebellious deficient qi, unless heavy minerals are used to suppress and descend it, the hardness cannot be quickly eliminated, nor can belching be instantly stopped. *Daizheshi* (Hematitum) possesses the red color of the South, enters and communicates with the Heart; its hardness removes fullness, and its weight removes belching. Used as an assistant herb, it addresses the branch symptoms urgently. *Renshen* and *Dazao* tonify deficiency while residual pathogens remain, addressing the root preemptively. Supporting righteous qi to drive out pathogens allows the spirit to settle. If *Qinh* and *Lian* were used to drain the heart, how could the faint yang be protected from extinction? Decocting *Xuanfuhua* and *Banxia*, and mixing with powdered *Daizheshi*, is best for treating stubborn phlegm knotted in the chest and diaphragm, or surging saliva. Adding *Renshen* is very effective for cases with deficiency.
*Ganjiang Huanglian Huangqin Renshen Tang* (Dried Ginger, Coptis, Scutellaria, and Ginseng Decoction):
Indicated for vomiting immediately after food intake following cold damage treated with vomiting or purgation. This is caused by cold pathogenic factors repelling heat into the upper jiao. Although there is no epigastric hardness, the root of the disease lies in the heart, hence half the dose of the *Xie Xin* formula is used. *Ganjiang* disperses cold in the upper jiao; *Huangqin* and *Huanglian* clear heat in the epigastrium; *Renshen* unblocks rebellious qi, thereby harmonizing cold and heat to achieve balance. *Shengjiang* and *Banxia* are removed because the deficient stomach cannot tolerate acrid dispersion; *Gancao* and *Dazao* are omitted because vomiting is unfavorable to sweet flavors. For patients with vomiting accompanied by heat, fragrant and aromatic formulas containing *Sha* (Amomum), *Ju* (Citrus Peel), *Jiegeng* (Platycodon Root), and *Banxia* are unsuitable; taking this formula results in comfort. After erroneous perspiration, if water and medicine cannot enter the mouth, it is called *shui ni* (water rebellion); after erroneous vomiting or purgation, if food is vomited immediately upon entry, it is called *shi ge* (food gridlock). This distinguishes injury to lung qi from injury to stomach qi. Immediate vomiting without retention indicates the image of fire flaming upward, so bitter-cold herbs outweigh acrid-hot ones. It is not named *Xie Xin Tang* because that formula is specifically for epigastric hardness. One must understand that cold and heat knotting at the epigastrium forms *pi* (fullness); cold and heat obstructing at the epigastrium forms *ge ni* (rebellion). The source is the same, but the manifestations differ.
*Chishizhi Yuyuliang Tang* (Red Halloysite and Metastone Decoction):
Following purgation, if diarrhea persists, and administering *Lizhong Tang* (Regulate the Middle Decoction) worsens the dysentery, this indicates the gate of the stomach is insecure, and there is collapse of the lower jiao. Gan, Jiang, Ren, and Zhu (Licorice, Ginger, Ginseng, Atractylodes) can tonify the deficiency of the central qi, but are insufficient to secure the leakage of the large intestine's fatty tissue. Therefore, for diarrhea located in the lower jiao, the principles of *Lizhong* cannot achieve success. The insecurity of the large intestine is still attributed to the stomach; the failure of the gate to close is still attributed to the spleen. Earth deficiency failing to control water requires tonifying earth. However, aromatic herbs inherit the transformation of Jia and Yi (Wood), which earth fears. One must select herbs inheriting the transformation of Wu Earth to cultivate earth and control water to succeed. Stones are the rigid aspect of earth. Both stones are結ings of earth's essence and qi; their sweet taste returns to the spleen, their qi is mild, and their nature is stable. They are used to reinforce the dam and calm earth and water, surpassing the efficacy of herbs. Moreover, *Chishizhi* (Red Halloysite) is red, entering Bing Fire, assisting fire to generate earth; *Yuyuliang* (Metastone) is yellow, entering Wu Earth, solidifying the stomach and astringing the intestines. Used to treat the branch of the lower jiao, it actually cultivates the root of the central palace. This syndrome involves earth deficiency without fire deficiency, so *Ganjiang* and *Fuzi* are unsuitable. The original text states: "If diarrhea continues, promote urination." This shows it differs from *Taohua Tang* (Peach Kernel Decoction). For lower jiao collapse, using these two substances as the base, taken with *Renshen* decoction, is most effective.
*Didang Tang/Wan* (Resist Directly Decoction/Pill):
Ingredients: *Shuizhi* (Leech), *Dahuang* (Rhubarb Root), *Mengchong* (Blue Bottle Fly Larva), *Taoren* (Peach Seed).
In Taiyang disease lasting six or seven days, if exterior symptoms persist, the intensity of yang qi is evident. The pulse should be large but is instead minute; it should be floating but is instead deep. Deep indicates interior location; one would expect *jie xiong* (chest binding) symptoms, yet there is none, indicating the disease is not in the upper jiao. Minute pulses indicate absence of yang, yet the patient goes mad, indicating the disease is not in the qi level. Generally, yang diseases ascend to the extreme and then descend, indicating heat is in the lower jiao. Untreated lower jiao pathology leads to hardness and fullness in the hypogastrium, indicating heat knotting in the bladder, which should cause urinary retention (*long bi*). Yet urine flows freely. This indicates the qi transformation of the lung in the upper jiao is functioning, but nutritive qi in the meridians is obstructed. People know internal heat causes urinary obstruction; here, heat knots in the bladder, yet urine is free, indicating urination depends on lung qi. When yang is excessive, yin must be deficient; when qi prevails, blood must be diseased. Stagnant heat knotted internally in the bladder causes nutritive blood to overflow externally into the meridians. Injury to nutritive qi results in minute and deep pulses; accumulation of stagnant blood results in hypogastric hardness. Blood stasis prevents flow; the heart cannot govern, the liver has nowhere to store, and the soul and spirit become restless, leading to madness, jaundice, or deep, knotted pulses. All result from stagnation of nutritive qi. Judging by free urination, we confirm the disease is in the blood level without error.
If stagnant blood is not removed, new blood cannot be generated; if nutritive qi does not flow, the five zang organs become blocked, and death follows swiftly. Qibo said: "If blood is clear and qi is sluggish, rapid purging exhausts qi; if blood is turbid and qi is sluggish, rapid purging unblocks the meridians." Only the most potent agents can reach the nest and shoulder this responsibility. *Shuizhi* (Leech) is skilled at drinking blood among insects; *Mengchong* (Blue Bottle Fly Larva) is fierce at sucking blood among flying insects. Here, land and water creatures skilled at removing blood are used to attack the stasis, utilizing similar qi attraction. Assisted by *Taoren* to push out the old and generate the new, and *Dahuang*'s bitter cold to cleanse pathogenic heat, it is named *Didang* (Resist Directly), meaning striking directly at the target. If there is heat but no madness, and abdominal fullness but no hardness, the dosage should be reduced and made into pills for slow treatment. If exterior symptoms resolve, but the hypogastrium is knotted, urgent, and full, and the person resembles madness, this has transferred to the Yangming stage. Use *Taoren* and *Guizhi* in *Tiaowei Chengqi Tang* (Regulate the Stomach and Order Qi Decoction) to mildly purge; when the stomach harmonizes, recovery occurs.
A question arises: Blood moves with heat, why does it knot here? Bladder heat causes urinary obstruction, why is it free here? The answer: The Chong Mai (Penetrating Vessel) is the Sea of Blood, located above the lower abdomen; the bladder is at the bottom. If bladder heat is present with abundant blood, blood flows down and does not accumulate; if bladder heat is present with scant blood, blood coagulates and knots in the lower abdomen. Water enters the stomach, is transported up to the spleen and lungs, and down to the bladder. The bladder is the official of the reservoir, relying entirely on spleen and lung qi transformation for fluid excretion. With heat in the lower jiao, if upper and middle jiao qi transformation is unaffected, urine flows freely. Obstruction of the bladder is *long*, due to Taiyin insecurity; incontinence is due to Taiyin failure to hold. Zhang Zhongjing formulated *Da Qinglong Tang*, *Da Chaihu Tang*, and *Baihu Tang* to treat formless heat knotting in the three yang stages. The heat-excess treated by the three *Chengqi* formulas involves fecal matter; the solid knotting treated by *Taoren* and *Didang* involves blood stasis. Within the tangible, there is a distinction between qi and blood. Whenever Zhang Zhongjing uses *Xiaoshi* (Niter) and *Dahuang*, it is to cleanse heat and remove filth, not to remove blood. Later generations exclusively contrasted qi and blood levels, mistaking feces for blood, and erroneously promoted *Dahuang* as a blood-level herb. They did not know *Dahuang*'s aroma opens spleen qi and removes decay, hence the name *Chengqi* (Ordering Qi). Without *Taoren*, how can blood be broken? Without leech and fly larvae, how can hardness be attacked? Thus, blood-resolving formulas have degrees of potency. Any mass (*jia*) that does not dissipate and eventually takes shape is caused by blood stasis. Today's practitioners, failing to identify the cause, use qi-level herbs like *Sanleng* (Sparganium Rhizome), severely damaging primordial qi. As primordial qi declines, pathogenic qi easily knots. Feces are removed by qi movement; blood stasis becomes harder when qi is injured. Understanding this, using *Didang Wan* yields effects in treating masses, expelling parasites, and attacking toxins.
Note: *Shuizhi* is physically soft but inherently dangerous, secretly stealing human blood unnoticed. If swallowed accidentally with water, it lingers in the stomach, consuming blood, causing abdominal pain or not, leading to emaciation and death. Observing cattle rumens containing this worm reveals they are always thin, allowing inference for others. *Mengchong* flies high and far, specifically sucking cow blood, more ferocious than houseflies. Houseflies cause painful bites; if ingested, immediate abdominal pain occurs until expelled. Flying insects belong to yang, specifically targeting nutritive blood, refusing to stay in the stomach, differing from the yin toxicity of crawling insects. Zhang Zhongjing combines *Meng* and *Zhi* so that *Zhi* does not linger in the stomach, aided by *Dahuang* to cleanse. Toxins and blood stasis are both expelled without lingering harm. However, these two drugs attack toxin with toxin; they should not be used lightly unless pathogenic factors are firmly knotted and primordial qi is not deficient.
Above are forty-six formulas in total. Those such as *Guizhi Jia Gegen Tang* and *Gegen Jia Banxia Tang* are easiest to understand, so they are not discussed in detail. Formulas such as *Sini Tang* and *Zhenwu Tang* are borrowed by Taiyang; their discussions belong to their respective positions, and the classic texts are listed subsequently.