少阴病，四逆，泄利下重，其人或咳、或悸、或小便不利、或腹中痛者，四逆散主之。
四肢为诸阳之本，阳气不达于四肢，因而厥逆，故四逆多属于阴。此则泄利下重，是阳邪下陷入阴中。阳内而
阴反外，以致阴阳脉气不相顺接也。可知以手足厥冷为热厥、四肢厥寒为寒厥者，亦凿矣。条中无主证，而皆是
或然证，四逆下必有阙文。今以泄利下重四字，移至四逆下，则本方乃有纲目。或咳、或利、或小便不利，同小
青龙证；厥而心悸，同茯苓甘草证；或咳、或利、或腹中痛、或小便不利，又同真武证。种种是水气为患，不发
汗利水者，泄利下重故也。泄利下重，又不用白头翁汤者，四逆故也。此少阴枢机无主，故多或然之证。因取四
物以散四逆之热邪，随症加味以治或然证。此少阴气分之下剂也，所谓厥应下之者，此方是矣。
四逆散∶
甘草（炙） 枳实 柴胡 芍药
上四味，各十分，捣筛，白饮和服方寸匕，日三服。咳者加五味子、干姜各五分，并主下利。悸者加桂枝
五分。小便不利者加茯苓五分。腹中痛者加附子一枚，炮令坼。泄利下重者先以水五升，内薤白三升，煮取三
升，去滓，以散三方寸匕，内汤中，煮取一升半，分温再服。
此仿大柴胡之下法也。以少阴为阴枢，故去黄芩之苦寒、姜夏之辛散，加甘草以易大枣，良有深意。然服
方寸匕，恐不济事。少阳心下悸者加茯苓，此加桂枝。少阳腹中痛者加芍药，此加附子，其法虽有阴阳之别，恐
非泄利下重者宜加也。薤白性滑，能泄下焦阴阳气滞，然辛温太甚，荤气逼人，顿用三升，而入散三匕，只闻薤
气而不知药味矣。且加味俱用五分，而附子一枚、薤白三升，何多寡不同若是，不能不致疑于叔和编集之误耳。
少阴病，出现四肢厥冷、腹泻且伴有肛门坠胀感，如果患者兼见咳嗽、或心悸、或小便不通畅、或腹部疼痛等症状，应当使用四逆散主治。
四肢是诸阳经的根本，阳气不能通达于四肢，从而导致四肢厥逆，所以四肢厥冷多属于阴寒证。但此处伴有腹泻且肛门坠胀，说明是阳热邪气下陷进入阴分。阳气内郁而阴气反盛于外，导致阴阳脉气不能顺接。由此可知，认为以手足厥冷为热厥、以四肢厥寒为寒厥的观点，也是牵强附会的。原文条文中没有确立主证，而全是或然证（可能出现的症状），在“四逆”二字之下必定有脱文（缺失的文字）。现在将“泄利下重”这四个字移到“四逆”之下，那么这个方剂就有了纲领和目次。咳嗽、腹泻、小便不利，与小青龙汤证相同；四肢厥冷伴随心悸，与茯苓甘草汤证相同；咳嗽、腹泻、腹部疼痛、小便不利，又与真武汤证相同。种种情况都是水气为患，如果不采用发汗利水的方法治疗，是因为存在“泄利下重”的缘故。对于“泄利下重”，又不使用白头翁汤的原因，是因为存在“四肢厥冷”的缘故。这是少阴枢机功能失常，所以出现多种或然证。因此选取四味药物来疏散四肢厥冷的热邪，根据症状加减药物来治疗或然证。这是少阴气分证的泻下方剂，所谓“厥证应当用下法”，这个方剂就是例证。
以上四味药，各取十分，捣碎过筛，用白米汤调和，服用一方寸匕，每日三次。咳嗽者加五味子、干姜各五分，同时主治腹泻。心悸者加桂枝五分。小便不利者加茯苓五分。腹部疼痛者加炮制裂开的附子一枚。腹泻且肛门坠重者，先用水五升，加入薤白三升，煮取三升，去渣，将散剂三方寸匕放入药汤中，再煮取一升半，分两次温服。
此方仿效大柴胡汤的下法。因为少阴为阴枢，所以去掉黄芩的苦寒之性和生姜、半夏的辛散之性，加入甘草以替代大枣，其中确有深意。然而，服用一方寸匕的药量，恐怕不足以见效。少阳病心下悸动者加茯苓，此处加桂枝；少阳病腹部疼痛者加芍药，此处加附子，虽然其治法有阴阳的区别，但恐怕不适合用于“泄利下重”的患者。薤白性质滑利，能宣泄下焦阴阳之气滞，但其辛温之性太过强烈，荤腥气味逼人，一次性使用三升，却只加入散剂三方寸匕，只能闻到薤白的味道而尝不出药味了。而且其他加味都只用五分，而附子用一枚、薤白用三升，为何多少差异如此之大，不得不让人怀疑是王叔和编纂整理时的错误。
Shaoyin disease, characterized by cold extremities (Jue Ni), diarrhea with a sensation of heaviness in the lower rectum. If the patient also presents with cough, palpitations, difficulty in urination, or abdominal pain, Si Ni San (Four Counterflow Powder) is the primary formula to govern it.
The four limbs are the root of all Yang meridians. When Yang Qi fails to reach the four limbs, Jue Ni (cold extremities) occurs; thus, cold extremities mostly belong to Yin syndromes. However, here the presence of diarrhea with rectal heaviness indicates that Yang pathogenic factors have sunk into the Yin. Yang is constrained internally while Yin manifests externally, resulting in the failure of Yin and Yang pulse energies to connect smoothly. Therefore, the view that hand-foot coldness constitutes Re Jue (Heat Jue) and limb coldness constitutes Han Jue (Cold Jue) is also forced and inaccurate. The clause lacks a principal syndrome, consisting entirely of conditional symptoms (Huo Ran Zheng); there must be missing text after the term "Si Ni" (Four Counterflow). By moving the four characters "Xie Li Xia Zhong" (diarrhea with rectal heaviness) to follow "Si Ni," this formula then has a clear structure. Cough, diarrhea, and difficulty in urination correspond to Xiao Qing Long Tang (Minor Green Dragon Decoction) syndrome; cold extremities with palpitations correspond to Fu Ling Gan Cao Tang (Poria and Licorice Decoction) syndrome; cough, diarrhea, abdominal pain, and difficulty in urination correspond to Zhen Wu Tang (True Warrior Decoction) syndrome. These various conditions are caused by water qi pathology. The reason for not employing sweating and diuresis methods is precisely due to "diarrhea with rectal heaviness." The reason for not using Bai Tou Weng Tang (Belamcanda Root Decoction) for "diarrhea with rectal heaviness" is due to the presence of "cold extremities." This represents a dysfunction of the Shaoyin pivot mechanism, leading to multiple conditional symptoms. Thus, four herbs are selected to dissipate the heat pathogen causing cold extremities, and modifications are made according to symptoms to treat the conditional syndromes. This is a purgative formula for Shaoyin Qi-level disorders, exemplifying the principle that "Jue syndromes should be treated with purgation."
Si Ni San (Four Counterflow Powder):
Zhi Gan Cao (Roasted Glycyrrhizae Radix et Rhizoma) | Zhi Shi (Immature Bitter Orange Fruit) | Chai Hu (Bupleuri Radix) | Shao Yao (Peony Root)
These four ingredients, each taken in ten parts, are crushed and sifted. They are mixed with white rice decoction and administered as one Fang Cun Bi (a measure approx. 27ml) per dose, three times daily. For cough, add Wu Wei Zi (Schisandrae Fructus) and Gan Jiang (Dried Ginger) each in five parts; this also treats diarrhea. For palpitations, add Gui Zhi (Cinnamomi Ramulus) in five parts. For difficulty in urination, add Fu Ling (Poria) in five parts. For abdominal pain, add one Pao Fu Zi (Prepared Aconiti Lateralis Radix), roasted until cracked. For diarrhea with rectal heaviness, first boil Xie Bai (Allii Macrostemonis Bulbus) in five sheng of water with three sheng of the herb, reduce to three sheng, strain, then add three Fang Cun Bi of the powder to the decoction, boil again to obtain one and a half sheng, and divide into two warm doses.
This formula imitates the purgative method of Da Chai Hu Tang (Major Bupleurum Decoction). Since Shaoyin serves as the Yin pivot, Huang Qin (Scutellariae Radix)'s bitter cold nature and Sheng Jiang (Fresh Ginger) and Ban Xia (Pinelliae Tuber)'s acrid dispersing properties are removed; Gan Cao (Licorice Root) replaces Da Zao (Jujubae Fructus), which holds profound significance. However, a dose of one Fang Cun Bi may likely be insufficient. In Shaoyang syndrome, palpitations under the heart are treated by adding Fu Ling (Poria); here, Gui Zhi (Cinnamomi Ramulus) is added. In Shaoyang syndrome, abdominal pain is treated by adding Shao Yao (Peony Root); here, Fu Zi (Aconite Root) is added. Although their methods differ in Yin and Yang, they may not be suitable for patients with "diarrhea with rectal heaviness." Xie Bai (Allii Macrostemonis Bulbus) is slippery in nature and can drain stagnation of Yin and Yang Qi in the Lower Jiao, but its acrid-warm property is too intense, and its pungent odor is overwhelming. Using three sheng at once, yet only adding three Fang Cun Bi of powder, results in tasting only the Xie Bai rather than the medicinal flavor. Moreover, while other additions use five parts, why is there such a disparity between one piece of Fu Zi (Aconite Root) and three sheng of Xie Bai (Allii Macrostemonis Bulbus)? This discrepancy inevitably raises doubts about errors in Wang Shuhe's compilation.