（仲景）
治伤寒发热，汗出不解，阳邪入里，热结在里（里非三阴之里，乃胃腑也，此为少阳阳
明。三阴亦有转入阳明者，如太阴有桂枝加大黄汤，少阴有三大承气，厥阴一小承气，皆兼
阳明证也），心下痞 ，呕而下利；或往来寒热，烦渴谵语，腹满便秘，表证未除，里证又
急，脉洪或沉实弦数者（表证未除者，发热、头痛、胁痛、寒热仍在也；里证又急者，痞硬、
燥渴、谵狂、便秘也。脉沉实为在里，弦数者邪在少阳也，洪者邪在阳明也。其呕而下利者，
何亦用之？张兼善曰∶里虚者便虽难而勿攻，里实者虽吐利而可下，心烦喜呕，里热已甚，
结于胃
柴胡（八两） 半夏（半升） 黄芩 芍药（三两） 生姜（五两） 大枣（十二枚。
擘） 枳实
柴胡汤也。崔氏
此足少阳、阳明药也。表证未除，故用柴胡以解表；里证燥实，故用大黄、枳实以攻里
；芍药安脾敛阴（能泻肝火，使木不克土）；黄芩退热解渴；半夏和胃止呕；姜辛散而枣甘
缓，以调营卫而行津液。此表里交治，下剂之缓者也（周扬俊曰∶仲景于太阳入膀胱腑证，
则有五苓散；少阳兼阳明腑证，则有大柴胡汤；皆表里两解之法也。昂按∶此乃少阳阳明，
故加减小柴胡、小承气而为一方，少阳固不可下，然兼阳明腑证则当下，宜小承气汤，轻则
大柴胡汤。或问大柴胡汤泻也，桂枝人参汤补也，何为皆治下利心下痞硬。张兼善曰∶下之
早因作痞者，里虚协热而利也，以表里不解，故用桂枝人参解表和里；若伤寒发热，汗出不
解、心下痞硬、呕吐而下利者，此为实，故当以大柴胡下之。陶节庵曰∶伤寒邪热传里，须
看热气浅深用药∶三焦俱伤，则痞满燥实坚全见，宜大承气汤；邪在中焦，则有燥实坚三证，
宜调胃承气汤，加甘草和中，去枳朴者，恐伤上焦氤氲之气也；邪在上焦，则痞而实，宜小
承气汤，去芒硝者，恐伤下焦真阴也。若表证未除，里证又急，不得不下者，则用大柴胡汤
通表里而缓治之。大承气最紧，小承气次之，调胃又次之，大柴胡又次之，盖恐硝性躁急，
故不轻
（张仲景）
治疗伤寒发热，汗出后病证未解，阳邪传入体内，热邪结聚在里（这里的“里”并非指三阴经的里，而是指胃腑，这属于少阳与阳明合病。三阴经也有转入阳明的情况，例如太阴病有桂枝加大黄汤，少阴病有三首承气汤方剂，厥阴病有一首小承气汤，这些都兼有阳明证的特征），心下痞塞，呕吐且伴有腹泻；或者出现寒热往来、烦躁口渴、说胡话、腹部胀满、大便秘结，表证尚未解除，里证又十分紧急，脉象洪大或沉实弦数（所谓“表证未除”，是指发热、头痛、胁痛、寒热症状仍然存在；所谓“里证又急”，是指心下痞硬、干燥口渴、谵语狂乱、大便秘结。脉象沉实表示病邪在里，弦数表示邪气在少阳，洪大表示邪气在阳明。对于呕吐且伴有腹泻的情况，为什么也使用此方？张兼善说：里虚的人虽然大便困难但不可攻下，里实的人虽然有呕吐腹泻也可以攻下。心烦喜呕，说明里热已经很严重，结聚在胃……
柴胡（八两） 半夏（半升） 黄芩 芍药（三两） 生姜（五两） 大枣（十二枚，掰开） 枳实
这是柴胡汤的加减方。崔氏认为
此方是足少阳胆经和足阳明胃经的药物。表证未除，所以用柴胡来解表；里证燥实，所以用大黄、枳实来攻里；芍药安抚脾脏并收敛阴液（能泻肝火，使肝木不克制脾土）；黄芩退热解渴；半夏调和胃气止呕；生姜辛散而大枣甘缓，用来调和营卫并运行津液。这是表里同治，属于泻下方剂中较为缓和的一类（周扬俊说：张仲景对于太阳经邪气传入膀胱腑的证候，有用五苓散；少阳经兼有阳明腑证的，就有大柴胡汤；这都是表里双解的方法。汪昂按语：这属于少阳阳明合病，因此是在小柴胡汤和小承气汤基础上加减而成的一方。少阳病固然不可轻易攻下，但如果兼有阳明腑证则应当攻下，轻症用小承气汤，重症用大柴胡汤。有人问：大柴胡汤是泻下的，桂枝人参汤是补益的，为什么都能治疗下利和心下痞硬？张兼善说：因为攻下过早导致痞满的，是里虚导致的协热下利，因为表里都不解，所以用桂枝人参汤解表和里；如果是伤寒发热，汗出后病不解，心下痞硬，呕吐且伴有下利的，这是实证，所以应当用大柴胡汤攻下。陶节庵说：伤寒邪热传入体内，必须根据热气深浅来用药：如果三焦都受伤，那么痞、满、燥、实、坚全部出现，宜用大承气汤；邪气在中焦，则有燥、实、坚三个证候，宜用调胃承气汤，加甘草以和中，去掉枳实、厚朴，是恐怕损伤上焦氤氲之气；邪气在上焦，则痞而且实，宜用小承气汤，去掉芒硝，是恐怕损伤下焦真阴。如果表证未除，里证又急，不得不攻下的，就用大柴胡汤通治表里并缓和地治疗。大承气汤最峻猛，小承气汤次之，调胃承气汤再次之，大柴胡汤又次之，大概是担心芒硝药性躁急，所以不轻易……
(Zhang Zhongjing)
Treats Shanghan (Cold Damage) with fever, where sweating does not resolve the condition. Yang pathogenic factors enter the interior, and heat binds in the interior (Here, "interior" does not refer to the interior of the Three Yin meridians, but rather the Stomach Fu-organ; this belongs to Shaoyang-Yangming combined disease. The Three Yin meridians can also transform into Yangming, such as Taiyin using Guizhi Jiada Huang Tang [Cinnamon Twig plus Rhubarb Decoction], Shaoyin having three Chengqi formulas, and Jueyin having one Xiaochengqi Tang [Minor Order the Qi Decoction]; all these involve Yangming syndrome characteristics). There is epigastric fullness and stuffiness (Xinxia Pi), vomiting accompanied by diarrhea; or there is alternating chills and fever, irritability, thirst, delirium, abdominal fullness, constipation. The exterior syndrome has not been resolved, while the interior syndrome is urgent. The pulse may be flooding (Hong) or deep, solid, wiry, and rapid (Chen Shi Xian Shu). ("Exterior syndrome not resolved" means fever, headache, hypochondriac pain, and chills/fever persist; "Interior syndrome urgent" means epigastric hardness, dry thirst, delirium/manic behavior, and constipation. A deep-solid pulse indicates pathogen in the interior; wiry-rapid indicates pathogen in Shaoyang; flooding indicates pathogen in Yangming. Regarding cases with vomiting and diarrhea, why is this formula used? Zhang Jianshan said: For those with interior deficiency, even if stool is difficult, do not attack with purgatives; for those with interior excess, even with vomiting and diarrhea, purgation is permissible. Irritability and frequent vomiting indicate severe interior heat binding in the stomach...)
Chaihu (Bupleuri Radix) (8 liang), Banxia (Pinelliae Tuber) (0.5 sheng), Huangqin (Scutellariae Radix), Shaoyao (Paeoniae Radix Alba) (3 liang), Shengjiang (Zingiberis Rhizoma Recens) (5 liang), Dazao (Jujubae Fructus) (12 pieces, split), Zhishi (Aurantii Fructus Immaturus).
This is a modification of Chaihu Tang (Bupleurum Decoction). Cui Shi considered:
This formula acts on the Foot-Shaoyang Gallbladder meridian and Foot-Yangming Stomach meridian. Since the exterior syndrome remains, Chaihu is used to release the exterior; since the interior syndrome involves dryness and excess, Dahuang (Rhei Radix et Rhizoma) and Zhishi are used to purge the interior; Shaoyao soothes the Spleen and astringes Yin (it can drain Liver fire, preventing Wood from overacting on Earth); Huangqin clears heat and relieves thirst; Banxia harmonizes the Stomach and stops vomiting; Shengjiang is pungent and dispersing, while Dazao is sweet and moderating, together they regulate Ying and Wei (Nutritive and Defensive levels) and promote fluid circulation. This treats both exterior and interior simultaneously; it is a mild form of purgative formula (Zhou Yangjun said: For Taiyang pathogen entering the Bladder Fu-organ, Zhang Zhongjing used Wuling San (Five-Ling Powder); for Shaoyang combined with Yangming Fu-organ syndrome, he used Dahuang Tang (Major Bile-Purging Decoction); both are methods of resolving exterior and interior simultaneously. Wang Ang's note: This is Shaoyang-Yangming combined disease, thus formed by modifying Xiao Chaihu Tang (Minor Bupleurum Decoction) and Xiaochengqi Tang. Shaoyang disease should generally not be purged, but if combined with Yangming Fu-organ syndrome, purgation is indicated. Mild cases use Xiaochengqi Tang, severe cases use Dahuang Tang. Question: Dahuang Tang is purgative, while Guizhi Renshen Tang (Cinnamon Twig and Ginseng Decoction) is tonifying; why do both treat diarrhea and epigastric fullness/hardness? Zhang Jianshan said: Fullness caused by premature purgation results from interior deficiency with協热 (collateral heat) diarrhea; because exterior and interior are unresolved, Guizhi Renshen Tang is used to release exterior and harmonize interior. If Shanghan fever persists after sweating, with epigastric fullness/hardness, vomiting, and diarrhea, this is excess, so Dahuang Tang should be used to purge. Tao Jian'an said: When Shanghan pathogenic heat transmits to the interior, medication must depend on the depth of heat: If all three Jiaozao (San Jiao) are injured, presenting fullness, distension, dryness, excess, and hardness, Da Chengqi Tang (Major Order the Qi Decoction) is suitable; if pathogen is in the Middle Jiao, presenting dryness, excess, and hardness, Tiaowei Chengqi Tang (Regulate the Stomach Order the Qi Decoction) is suitable, adding Gancao (Glycyrrhizae Radix et Rhizoma) to harmonize the middle, removing Zhishi and Houpo (Magnoliae Officinalis Cortex) to avoid damaging the misty Qi of the Upper Jiao; if pathogen is in the Upper Jiao, presenting fullness and excess, Xiao Chengqi Tang is suitable, removing Mangxiao (Natrii Sulfas) to avoid damaging the True Yin of the Lower Jiao. If exterior syndrome is unresolved and interior syndrome is urgent, requiring purgation, Dahuang Tang is used to unblock exterior and interior and treat gently. Da Chengqi Tang is the most intense, Xiao Chengqi Tang is next, Tiaowei Chengqi Tang is next, and Dahuang Tang is milder still, largely due to concern that Mangxiao's nature is restless and urgent, so it is not used lightly...)