主治水病也，旁治肺痈结胸。
考 证
葶苈大枣汤证曰∶肺痈、胸满胀、一身面目浮肿。
以上一方，葶苈捣丸如弹丸大。
大陷胸丸证曰∶结胸。
以上一方，葶苈半升。
己椒苈黄丸证曰∶肠间有水气。
以上一方，葶苈一两。
大陷胸丸，则水利而疾愈，然则葶苈之治水也明矣。
互 考
或问曰∶葶苈大枣汤、桔梗汤、桔梗白散，同治肺痈，而异其方，何也？为则答曰∶用
桔梗之证，浊唾腥臭，久久吐脓者也。用葶苈之证，浮肿清涕，咳逆喘鸣者也。故因其见证
而处方，不为病名所绊，斯为得也。
《淮南子》曰∶葶苈愈胀。为则按∶胀是水病也。
品 考
葶苈 有甜苦二种。而甜者不中用焉，本邦未出苦葶苈也。或曰∶关以东间有之。
主通利结毒也，故能治胸满、腹满、腹痛。及便闭、小便不利，旁治发黄、瘀血、肿脓。
考 证
大陷胸汤证曰∶从心下至少腹、硬满而痛。
以上一方，大黄六两。
小承气汤证曰∶腹微满、大便不通。
浓朴三物汤证曰∶痛而闭者。
大黄甘遂汤证曰∶少腹满、如敦状、小便微难。
大承气汤证曰∶腹满痛者。
大黄硝石汤证曰∶黄胆、腹满、小便不利。
桃核承气汤证曰∶少腹急结。
大黄牡丹汤证曰∶少腹肿痞。
大黄甘草汤，证不具也。
调胃承气汤证曰∶腹胀满。又曰∶大便不通。
以上九方，大黄皆四两。
大黄附子汤证曰∶胁下偏痛。
抵当汤证曰∶少腹硬满。
大黄黄连泻心汤证曰∶心下痞、按之濡。
桂枝加大黄汤证曰∶大实痛。
以上四方，大黄或三两、或二两、一两。而亦四两之例。
上历观此诸方。张仲景氏用大黄者，特以利毒而已。故各陪其主药，而不单用焉。合浓
朴、枳实，则治胸腹满。合黄连，则治心下痞。合甘遂、阿胶，则治水与血。合水蛭、虻虫、
桃仁，则治瘀血。合黄柏、栀子，则治发黄。合甘草，则治急迫。合芒硝，则治坚块也。学
者审诸，仲景方中用大黄者，不止于兹，而以其用之之征，显然着明于兹，故不复游赘也。
辨 误
世医之畏大黄也，不啻如蛇蝎。其言曰∶凡用大黄者，虽病则治乎损内而死。切问而无
其人，此承本草之讹而吠声者也，非耶！仲景氏用下剂，其亦多矣。可见大黄，攻毒之干莫
也。今也畏其利，而用铅刀，宜哉不能断沉 也。虽大下之后，仲景氏未尝补也，亦可以见
损内之说妄矣。凡药剂之投，拔病之未及以断其根，则病毒之动，而未能爽快，仍贯其剂也。
毒去而后爽快，虽千万人亦同。世医素畏下剂，故遽见其毒未去也，以为元气虚损，岂不亦
妄哉？
品 考
大黄 汉土产，有两品，黄色而润实者为良，所谓锦纹大黄也，本邦近者有称汉种大黄
者也
考证
葶苈大枣汤的适应证是：肺痈、胸部胀满、全身及面目浮肿。
以上一方中，葶苈捣碎制成如弹丸大小的药丸。
大陷胸丸的适应证是：结胸。
以上一方中，葶苈用量为半升。
己椒苈黄丸的适应证是：肠间有水气停留。
以上一方中，葶苈用量为一两。
在大陷胸丸方中，若水气得以下利则疾病痊愈，由此可见葶苈治疗水气病的功效是明确的。
互考
有人问：葶苈大枣汤、桔梗汤、桔梗白散都用于治疗肺痈，但方剂不同，为什么呢？我回答说：使用桔梗的证候，表现为浊唾腥臭，长期吐脓。使用葶苈的证候，表现为浮肿、清涕、咳嗽气逆、喘息有声。因此根据见证来处方，不被病名所束缚，这才是正确的做法。
《淮南子》说：葶苈能消除胀满。我按语认为：胀满是水气病的一种表现。
品考
葶苈有甜、苦两种。其中甜的不能使用，我国（日本）尚未出产苦葶苈。有人说：关东地区有出产。
主要作用是通利结聚之毒邪，因此能治疗胸满、腹满、腹痛。以及大便闭塞、小便不利，兼治发黄、瘀血、肿脓。
考证
大陷胸汤的适应证是：从心下至少腹部，硬满且疼痛。
以上一方中，大黄用量为六两。
小承气汤的适应证是：腹部轻微胀满、大便不通。
厚朴三物汤的适应证是：疼痛且大便闭塞。
大黄甘遂汤的适应证是：少腹胀满，形状如敦（古代盛食物的器具），小便微难。
大承气汤的适应证是：腹部胀满疼痛。
大黄硝石汤的适应证是：黄疸、腹部胀满、小便不利。
桃核承气汤的适应证是：少腹急迫拘急且有结块感。
大黄牡丹汤的适应证是：少腹肿胀痞块。
大黄甘草汤，其适应证记载不全。
调胃承气汤的适应证是：腹部胀满。又说：大便不通。
以上九方中，大黄用量均为四两。
大黄附子汤的适应证是：胁下偏侧疼痛。
抵当汤的适应证是：少腹硬满。
大黄黄连泻心汤的适应证是：心下痞塞，按之柔软。
桂枝加大黄汤的适应证是：剧烈的实痛。
以上四方中，大黄用量有的三两，有的二两，一两，但也遵循四两的常规。
综上所述观察这些方剂，张仲景使用大黄，仅仅是为了通利毒邪罢了。所以各配伍其主要药物，而不单独使用。配合厚朴、枳实，则治疗胸腹满；配合黄连，则治疗心下痞；配合甘遂、阿胶，则治疗水饮与瘀血；配合水蛭、虻虫、桃仁，则治疗瘀血；配合黄柏、栀子，则治疗发黄；配合甘草，则治疗急迫；配合芒硝，则治疗坚硬结块。学者们请仔细审察，仲景方中使用大黄的不仅仅只有这些，但其应用的征象在此处已明显清晰，故不再赘述。
辨误
世俗医生畏惧大黄，就像畏惧蛇蝎一样。他们说：凡是使用大黄的，即使病治好了，也会因损伤内脏而死。我深切询问并没有这样的人，这是沿袭本草书的错误而随声附和的人，不是吗！仲景使用攻下剂，次数也很多了。可见大黄是攻逐毒邪的关键药物。现在因为畏惧它的通利作用而使用钝刀（铅刀），当然不能切断沉重的东西。虽然经过大下之后，仲景也未曾进行补益，这也足以证明“损伤内脏”的说法是荒谬的。凡药剂的投用，如果在病根未除时就停止用药，那么毒邪的活动未能彻底清除，仍应继续给药。毒邪去除后身体才会爽快，千万人都是一样的道理。世俗医生素来畏惧攻下剂，所以一见毒邪未去，就认为是元气虚损，这难道不是荒谬的吗？
It primarily treats water diseases (Shuibing, disorders related to fluid metabolism and retention), and secondarily treats lung abscess (Fei Yong) and chest binding (Jie Xiong).
Evidence Examination
The syndrome of Tingli Dazao Tang is characterized by: lung abscess, chest fullness, and edema of the whole body and face.
In the above prescription, Tingli (Semen Lepidii / Semen Descurainiae) is pounded into pills the size of a bullet.
The syndrome of Daxianxiong Wan is characterized by: chest binding.
In the above prescription, the dosage of Tingli is half a sheng.
The syndrome of Jifeng Lihuang Wan is characterized by: water qi (fluid accumulation) in the intestines.
In the above prescription, the dosage of Tingli is one liang.
In Daxianxiong Wan, if water qi is discharged through urination or defecation, the illness is cured. Thus, it is clear that Tingli treats water diseases.
Mutual Examination
Someone asked: Tingli Dazao Tang, Jiegeng Tang, and Jiegeng Baisan all treat lung abscess, yet the prescriptions differ. Why? I answered: The indications for using Jiegeng (Radix Platycodi) are turbid saliva with a foul odor and long-term expectoration of pus. The indications for using Tingli are edema, clear nasal discharge, cough with counterflow qi (asthma), and wheezing. Therefore, one prescribes based on the manifestations, not being bound by the disease name; this is correct.
Huainanzi states: "Tingli cures distension." My commentary notes: Distension is a manifestation of water disease.
Product Examination
Tingli has two types: sweet and bitter. The sweet type is ineffective. Our country (Japan) does not produce bitter Tingli. Some say it is produced in the region east of the Pass.
It primarily promotes the unblocking and draining of accumulated toxic pathogens, thus treating chest fullness, abdominal fullness, and abdominal pain. It also treats constipation and difficult urination, and secondarily treats jaundice, blood stasis, and swelling/pus.
Evidence Examination
The syndrome of Daxianxiong Tang is characterized from the epigastrium down to the lower abdomen: hardness, fullness, and pain.
In the above prescription, the dosage of Dahuang (Radix et Rhizoma Rhei) is six liang.
The syndrome of Xiao Chengqi Tang is characterized by: slight abdominal fullness and constipation.
The syndrome of Houpo Sanwu Tang is characterized by: pain accompanied by constipation.
The syndrome of Dahuang Gansui Tang is characterized by: fullness of the lower abdomen, shaped like a Dun (ancient vessel), and slightly difficult urination.
The syndrome of Da Chengqi Tang is characterized by: abdominal fullness and pain.
The syndrome of Dahuang Xiaoshi Tang is characterized by: jaundice, abdominal fullness, and difficult urination.
The syndrome of Taohe Chengqi Tang is characterized by: urgency and clumping in the lower abdomen.
The syndrome of Dahuang Mudan Tang is characterized by: swelling and痞 (blockage/fullness) in the lower abdomen.
Dahuang Gancao Tang: the syndrome description is incomplete.
The syndrome of Tiaowei Chengqi Tang is characterized by: abdominal fullness. It also states: constipation.
In the above nine prescriptions, the dosage of Dahuang is four liang.
The syndrome of Dahuang Fuzi Tang is characterized by: unilateral pain in the hypochondrium.
The syndrome of Didang Tang is characterized by: hardness and fullness of the lower abdomen.
The syndrome of Dahuang Huanglian Xiexin Tang is characterized by: epigastric痞 (blockage/fullness), which is soft upon palpation.
The syndrome of Guizhi Jiadahuang Tang is characterized by: severe excess pain.
In the above four prescriptions, the dosage of Dahuang varies between three liang, two liang, and one liang, but still follows the pattern of four liang.
Having observed these prescriptions comprehensively, Zhang Zhongjing used Dahuang solely to promote the unblocking and draining of toxic pathogens. Therefore, it was never used alone but always paired with its principal herb. Paired with Houpo (Cortex Magnoliae Officinalis) and Zhishi (Fructus Aurantii Immaturus), it treats chest and abdominal fullness. Paired with Huanglian (Rhizoma Coptidis), it treats epigastric痞. Paired with Gansui (Radix Kansui) and Ejiao (Colla Corii Asini), it treats water and blood disorders. Paired with Shuizhi (Hirudo), Mengchong (Tabanus), and Taoren (Semen Persicae), it treats blood stasis. Paired with Huangbai (Cortex Phellodendri) and Zhizi (Fructus Gardeniae), it treats jaundice. Paired with Gancao (Radix Glycyrrhizae), it treats urgency. Paired with Mangxiao (Natrii Sulfas), it treats hard masses. Scholars should examine this carefully. Although Zhang Zhongjing used Dahuang in more prescriptions than listed here, the evidence of its application is clearly demonstrated here, so no further elaboration is needed.
Correction of Errors
Physicians of the world fear Dahuang as much as they fear snakes and scorpions. They say: "Whoever uses Dahuang may cure the disease but will die from damaging the internal organs." Having inquired deeply, I found no such cases. These people are merely barking up the wrong tree, following errors in Materia Medica texts, are they not? Zhang Zhongjing used purgative formulas many times. This shows that Dahuang is the key agent for attacking toxic pathogens. Now, fearing its purgative action, one uses a lead knife (a dull blade); naturally, it cannot cut through heavy objects. Even after severe purgation, Zhang Zhongjing did not use tonics, which proves that the notion of "damaging internal organs" is absurd. When administering medicine, if one stops before the root of the disease is eradicated, the pathogenic factors remain active and cannot be expelled satisfactorily; thus, the medication must continue. Only after the toxin is removed will the patient feel relieved; this applies to everyone. Physicians who fear purgatives see the persistence of toxins and immediately assume it is due to deficiency of Yuan Qi (Original Qi); is this not absurd?
Product Examination
Dahuang is native to Han land (China). There are two varieties; the yellow, moist, and solid ones are superior, known as Jinwen Dahuang (Brocade-patterned Rheum). Recently, our country has also referred to them as Han-type Dahuang.