治服桂枝汤。或下之。仍头项强痛。翕翕发热无汗。心下满微痛。
小便不利者。
芍药（三两） 甘草（二两炙） 生姜（三两） 茯苓（三两） 白术（三两） 大枣
（十
上六味。以水八升。煮取三升。去滓。温服一升。小便利则愈。
歌曰 术芍苓姜三两均。枣须十二效堪珍。炙甘二两中输化。水利邪除立法新。
蔚按。上节言太阳之气内陷于脾而不能外达。此节言太阳之气内陷于脾而不能转输也。
用桂
丝入扣也。或者悔桂枝汤之误而下之。无如表证悉具。转因误下而陷于脾。以致心下满微痛
小便不利。其病机在于小便不利四字。桂枝之长于解肌。不长于利水。服五苓散多饮暖水以
出
。脾不能转输其津液。故小便不利。今用桂枝汤去桂而加白术茯苓。则转输灵而小便自利。
小便利而太阳之气达于内外。而内外之邪俱净矣。又按。经方分两轻重。变化难言。有方中
以分两最重为君者。如小柴胡汤。柴胡八两余药各三两之类是也。有方中数味平用者。如桂
枝
而以猪苓为君是也。有方中分两甚少而得力者。如甘草附子汤中。为使之桂枝四两而所君之
甘草只二两是也。又如炙甘草汤中。为使之地黄一斤而所君之炙甘草只四两是也。然此虽轻
重莫测。而方中有是药而后主是名。未有去其药而仍主其名。主其名即所以主其功。如此证
头项强痛翕翕发热。为太阳桂枝证仍在。因其误治。遂变其解肌之法而为利水。水利则满减
热除而头项强痛亦愈。主方在无药之处。神乎其神矣。
治疗服用桂枝汤后，或者经过攻下法治疗，仍然出现头项强痛、发热如热气覆盖（翕翕发热）、无汗、胃脘部胀满且轻微疼痛、小便不通利的情况。
芍药（三两） 甘草（二两，炙） 生姜（三两） 茯苓（三两） 白术（三两） 大枣（十二枚，擘开）
以上六味药，用水八升，煮取三升，滤去药渣，温服一升。小便利则病愈。
歌诀曰：白术、芍药、茯苓、生姜各三两剂量均等。大枣需用十二枚，疗效值得珍视。炙甘草二两以助中焦输布化源。水液通利则邪气去除，此立法新颖独特。
蔚按（陈念祖自注）：上一节论述的是太阳之气内陷于脾而不能外达；这一节论述的是太阳之气内陷于脾而不能转输津液。使用桂枝汤如同丝线入扣般契合病情。有人后悔误用桂枝汤而改用攻下法，无奈表证依然存在，反而因误下导致邪气陷入脾脏，以致出现胃脘部胀满微痛、小便不利。其病机关键在于“小便不利”这四个字。桂枝擅长解肌发表，却不擅长利水。服用五苓散时需多饮暖水以助汗出。由于脾不能转输津液，所以小便不利。现在使用桂枝汤去掉桂枝而加入白术和茯苓，则脾的转输功能恢复灵便，小便自然通利。小便利了，太阳之气就能通达内外，内外的邪气也就都清除干净了。
又按：经方的分量轻重，变化难以言尽。有的方剂中以分量最重的药物为君药，例如小柴胡汤中，柴胡用八两，其余药物各三两，就是这样。有的方剂中几味药平起平坐使用，例如猪苓汤中，以猪苓为君药。有的方剂中药量很少却效力显著，例如甘草附子汤中，作为使药的桂枝用四两，而作为君药的甘草只用二两，就是这样。又如炙甘草汤中，作为使药的地黄用一斤，而作为君药的炙甘草只用四两，也是这样。然而虽然分量轻重难以揣测，但方中有某种药，才以此药命名方名。没有去掉某味药却还保留原方名的道理。保留原名即意味着保留该药的功效。像这种病症，头项强痛、翕翕发热，说明太阳桂枝证仍然存在。因为误治，于是改变了解肌的方法而转为利水。水液通利则胀满消除、热退而头项强痛也痊愈。主治的关键在于看似无药之处，真是神妙至极啊。
Indicated for cases where, after taking Guizhi Tang (Cinnamon Twig Decoction) or following purgation therapy, symptoms such as stiffness and pain in the head and neck, feverish sensation with a covering heat (Xi Xi Fa Re), absence of sweating, fullness and slight pain in the epigastrium, and difficulty in urination persist.
Shaoyao (White Peony Root, 3 liang) Gancao (Licorice Root, 2 liang, honey-fried) Shengjiang (Fresh Ginger, 3 liang) Fuling (Poria, 3 liang) Baizhu (Atractylodes Macrocephala Rhizome, 3 liang) Dazao (Jujube Fruit, 12 pieces, split open)
Take the above six ingredients, add eight sheng of water, decoct to obtain three sheng, remove the dregs, and take one sheng warm. The condition will resolve when urination becomes normal.
Song verse:
Baizhu, Shaoyao, Fuling, and Shengjiang are equal at three liang each.
Twelve Jujubes are required; their efficacy is precious.
Two liang of Honey-fried Licorice aids the transformation and transportation of the Middle Jiao.
When water passages clear, pathogenic factors are expelled; this prescription method is novel.
Commentary by Wei (Chen Nianzu): The previous section discussed Taiyang Qi sinking into the Spleen and failing to reach the exterior; this section discusses Taiyang Qi sinking into the Spleen and failing to transport fluids. Using Guizhi Tang fits the condition like thread through a buttonhole. Some regret the error of using Guizhi Tang and resort to purgation, but since exterior syndromes remain complete, the erroneous purgation causes the pathogen to sink into the Spleen, resulting in epigastric fullness, slight pain, and difficulty in urination. The key to the pathogenesis lies in the four characters "difficulty in urination." Guizhi excels at releasing the muscle layer but does not excel at promoting diuresis. When taking Wuling San (Five-Ingredient Powder with Poria), one should drink plenty of warm water to induce sweat. Because the Spleen fails to transport and distribute body fluids, urination is difficult. Now, by removing Guizhi from Guizhi Tang and adding Baizhu and Fuling, the Spleen's transport function becomes agile, and urination naturally clears. Once urination is smooth, Taiyang Qi can circulate internally and externally, clearing pathogenic factors both inside and out.
Furthermore: The dosage weights in classical formulas vary subtly and are hard to describe fully. In some formulas, the herb with the heaviest dosage serves as the Jun (Emperor) herb, such as Xiaochaihu Tang (Minor Bupleurum Decoction), where Chaihu (Bupleurum Root) is used in 8 liang while other herbs are 3 liang. In some formulas, several herbs are used in balanced dosages, such as Zhu Ling Tang (Polyporus Decoction), where Zhu Ling (Polyporus) serves as the Jun herb. In some formulas, small dosages yield significant effects, such as in Gancao Fuzi Tang (Licorice and Aconite Decoction), where Guizhi (Cinnamon Twig) acts as the Shi (Envoy) herb in 4 liang, while the Jun herb Gancao (Licorice) is only 2 liang. Similarly, in Zhigancao Tang (Honey-Fried Licorice Decoction), Dihuang (Rehmannia Root) acts as the Shi herb in 1 jin, while the Jun herb Zhigancao (Honey-Fried Licorice) is only 4 liang. Although these weight variations are unpredictable, the name of a formula is derived from its principal herb; it is inconceivable to remove an herb yet retain the original formula name. Retaining the name implies retaining the herb's function. In this case, stiffness and pain in the head and neck, along with a feverish sensation, indicate that the Taiyang Guizhi syndrome persists. Due to erroneous treatment, the method shifts from releasing the muscle layer to promoting diuresis. When water metabolism clears, fullness subsides, heat dissipates, and head/neck stiffness resolves. The mastery of this prescription lies in its subtle application where herbs seem absent, demonstrating profound therapeutic skill.