桂枝（四两去皮味辛热） 甘草（四两炙味甘平） 白术（三两味甘平） 人参
（三两味甘温） 干姜（三两味辛热）
上五味。以水九升。先煮四味。取五升。内桂。更煮。取三升。温服一升。日再。夜
一服。
表未解者。辛以散之。里不足者。甘以缓之。此以里气大虚。表里不解。故加桂枝
甘草于理中汤也。
张兼善云。大柴胡汤。泻也。桂枝人参汤。补也。皆治下利。心下痞硬。若伤寒发
热。汗出不解。心下痞硬。呕吐而下利者。表和而里病也。以心中痞硬。故为实。当以
大柴胡汤下之。二者心下痞硬虽同。而虚实之症有异。故用药有攻补之别也。
伤寒大下
后。复发汗。心下痞。恶寒者。表未解也。不可攻痞。当先解表。表解乃可攻
痞。解表宜桂枝汤。攻痞宜大黄黄连泻心汤。
大下后复发汗。则表里之邪当悉已。此心下痞而恶寒者。表里之邪。俱不解也。因
表不解而下之。为心下痞。先与桂枝汤解表。表解。乃与大黄黄连泻心汤攻痞。内经曰。
从外之内。而盛于内者先治其外而后调其内。
活人云。大抵结胸与痞。皆应下。然表未解者。不可攻也。
伤寒发热。汗出不解。心中痞硬。呕吐而下利者。大柴胡汤主之。
伤寒发热。寒已成热也。汗出不解。表和而里病也。吐利心腹濡软。为里虚。呕吐
而下利。心腹痞硬者。是里实也。与大柴胡汤。以下里热。
病如挂枝证。头不痛。项不强。寸脉微浮。胸中痞硬。气上冲咽喉。不得息者。此
为胸有寒也。当吐之。宜瓜蒂散。
病如桂枝证。为发热。汗出。恶风。言邪在表也。头痛项强。为桂枝汤证具。若头
不痛。项不强。则邪不在表而传里也。浮为在表。沉为在里。今寸脉微浮。则邪不在表。
亦不在里。而在胸中也。胸中与表相应。故知邪在胸中者。犹如桂枝证。而寸脉微浮也。
以胸中痞硬。上冲咽喉。不得息。知寒邪客于胸中。而不在表也。千金
曰。气浮上部。填塞心胸。胸中满者。吐之则愈。与瓜蒂散。以吐胸中之邪。
桂枝（四两，去皮，味辛、性热） 甘草（四两，炙用，味甘、性平） 白术（三两，味甘、性平） 人参（三两，味甘、性温） 干姜（三两，味辛、性热）
以上五味药。用水九升。先煮前四味药。取五升药液。加入桂枝。再煮。取三升药液。温服一升。每日两次。夜间一次服用。
表证未解除的，用辛味药来发散它。里气不足的，用甘味药来缓急补虚。这是因为里气极度虚弱，表里同病且均未解除，所以在理中汤的基础上加桂枝和甘草。
张兼善说：大柴胡汤是泻实的方法。桂枝人参汤是补虚的方法。两者都治疗下利（腹泻）、心下痞硬（胃脘部堵塞感且按之坚硬）。如果伤寒发热，汗出后病不解，出现心下痞硬、呕吐并伴有下利的，这是表证已解而里证为病的表现。因为心中痞硬，所以判断为实证，应当用大柴胡汤攻下。这两种情况虽然都有心下痞硬的症状，但虚实性质不同，所以用药有攻邪与补虚的区别。
伤寒经过猛烈攻下之后，又再次发汗，导致心下痞满，同时伴有恶寒的，说明表证仍未解除。此时不可攻逐痞满，应当先解表证。表证解除后，才可以攻逐痞满。解表适宜用桂枝汤。攻逐痞满适宜用大黄黄连泻心汤。
经过猛烈攻下后又再次发汗，按理说表里的邪气应当都已消除。现在出现心下痞满且恶寒，说明表里之邪都没有解除。因为表证未解而误用攻下法，导致了心下痞满。先给予桂枝汤解除表证。表证解除后，再给予大黄黄连泻心汤攻逐痞满。《内经》说：病邪从外部传入内部，并在内部盛行的，应当先治疗外部，然后再调理内部。
《活人书》说：大体上结胸证与痞证，都应当使用下法。然而表证未解除的，不可攻下。
伤寒发热，汗出后病仍不解除，心中痞硬，呕吐并伴有下利的，主治方剂是大柴胡汤。
伤寒发热，说明寒邪已经化热。汗出后病仍不解除，说明表证已解而里证为病。呕吐、下利且心腹部柔软无力的，属于里虚证。呕吐并伴有下利，且心腹部痞塞坚硬的，属于里实证。给予大柴胡汤，以攻下里热。
病症类似桂枝汤证，但头不痛，项不强，寸脉微浮，胸中痞塞坚硬，气向上冲至咽喉，呼吸不畅的，这是胸中有寒饮（痰饮等阴邪）。应当采用涌吐法。适宜用瓜蒂散。
病症类似桂枝汤证，表现为发热、汗出、恶风，说明邪气在表。头痛、项强，是桂枝汤证的典型表现。如果头不痛、项不强，则说明邪气不在表，而是传入了里。脉浮表示病在表，脉沉表示病在里。现在寸脉微浮，说明邪气不在表，也不在里，而是在胸中。胸中与体表相应，所以知道邪气在胸中的，就像桂枝汤证一样，且寸脉微浮。因为胸中痞塞坚硬，气上冲咽喉，呼吸不畅，可知寒邪客居于胸中，而不在体表。《千金方》说：气浮于上部，填塞心胸，导致胸中胀满的，通过涌吐法可以痊愈。给予瓜蒂散，以涌吐胸中的邪气。
Cinnamon Twig (Guizhi, *Ramulus Cinnamomi*, four liang, bark removed, acrid and hot) Licorice Root (Gancao, *Radix Glycyrrhizae*, four liang, honey-fried, sweet and neutral) Atractylodes Rhizome (Baizhu, *Rhizoma Atractododis Macrocephalae*, three liang, sweet and neutral) Ginseng Root (Renshen, *Radix Ginseng*, three liang, sweet and warm) Dried Ginger (Ganjiang, *Rhizoma Zingiberis Preparatum*, three liang, acrid and hot)
These five herbs. Use nine sheng of water. First decoct the first four herbs. Obtain five sheng of liquid. Add Cinnamon Twig. Decoct further. Obtain three sheng of liquid. Take one sheng warm. Twice daily. Once at night.
When the exterior syndrome is unresolved, use acrid substances to disperse it. When interior deficiency exists, use sweet substances to moderate and tonify. This is because the interior qi is severely deficient, and both exterior and interior syndromes are unresolved; therefore, Cinnamon Twig and Licorice Root are added to Lizhong Tang (Middle-Boosting Decoction).
Zhang Jianshan stated: Dachaihu Tang (Major Bupleurum Decoction) is a method of purging excess. Guizhi Renshen Tang (Cinnamon Twig and Ginseng Decoction) is a method of tonifying deficiency. Both treat diarrhea and epigastric fullness with hardness. If typhoid fever presents with heat, sweating that does not resolve the condition, epigastric fullness with hardness, vomiting, and diarrhea, this indicates the exterior is resolved while the interior is diseased. Because of the epigastric fullness and hardness, it is judged as an excess pattern, and Dachaihu Tang should be used to purge. Although both conditions present with epigastric fullness and hardness, their nature differs between excess and deficiency; thus, the medications differ between attacking pathogens and tonifying.
After severe purgation in typhoid fever, followed by repeated sweating, if epigastric fullness occurs accompanied by aversion to cold, the exterior syndrome remains unresolved. One must not attack the fullness at this time; instead, one should first resolve the exterior. Only after the exterior is resolved can the fullness be attacked. To resolve the exterior, Guizhi Tang (Cinnamon Twig Decoction) is suitable. To attack the fullness, Dahuang Huanglian Xiexin Tang (Rhubarb, Coptis, and Scutellaria Heart-Purging Decoction) is suitable.
After severe purgation and subsequent sweating, theoretically, both exterior and interior pathogens should have been eliminated. The current presentation of epigastric fullness and aversion to cold indicates that neither exterior nor interior pathogens have been resolved. Because the exterior was unresolved when purgation was mistakenly applied, epigastric fullness resulted. First administer Guizhi Tang to resolve the exterior. Once the exterior is resolved, then administer Dahuang Huanglian Xiexin Tang to attack the fullness. The *Neijing* states: When pathogenic factors enter from the exterior and become prevalent internally, one should first treat the exterior and subsequently regulate the interior.
The *Huoren Shu* states: Generally speaking, Jie Xiong (Chest Binding) and Pi (Glomus/Fullness) syndromes should both be treated with purgation. However, if the exterior syndrome is unresolved, purgation is contraindicated.
Typhoid fever with heat, sweating that does not resolve the condition, epigastric fullness with hardness, vomiting, and diarrhea: Dachaihu Tang is the primary formula.
Typhoid fever with heat indicates that cold has transformed into heat. Sweating without resolution indicates the exterior is resolved but the interior is diseased. Vomiting and diarrhea with a soft and flaccid abdomen indicate interior deficiency. Vomiting and diarrhea with epigastric and abdominal fullness and hardness indicate interior excess. Dachaihu Tang is given to purge interior heat.
The condition resembles Guizhi Tang syndrome, but without headache or stiff neck, with a slightly floating pulse at the cun position, epigastric fullness and hardness, qi rushing upward to the throat causing breathing difficulty, this is termed "cold in the chest" (accumulation of phlegm-fluids or yin pathogens in the chest). It should be treated with emesis. Gouti San (Melon Seed Powder) is suitable.
A condition resembling Guizhi Tang syndrome involves heat, sweating, and aversion to wind, indicating pathogenic factors in the exterior. Headache and stiff neck constitute the complete Guizhi Tang syndrome. If there is no headache or stiff neck, the pathogen is not in the exterior but has transmitted inward. A floating pulse indicates disease in the exterior; a deep pulse indicates disease in the interior. Currently, the cun pulse is slightly floating, indicating the pathogen is neither in the exterior nor in the interior, but in the chest. The chest corresponds to the exterior; thus, knowing the pathogen is in the chest is similar to Guizhi Tang syndrome, presenting with a slightly floating cun pulse. Due to epigastric fullness and hardness, qi rushing to the throat, and breathing difficulty, it is known that cold pathogens reside in the chest, not in the exterior. The *Qianjin Fang* states: When qi floats to the upper part, filling the heart and chest, causing chest fullness, emesis leads to cure. Gouti San is given to emetic the pathogens from the chest.