葱白（四茎） 干姜（一两） 附子（一枚生用去皮破八片）
上三味。以水三升。煮取一升。去滓。分温再服。
成注引内经曰。肾苦燥。急食辛以润之。葱白之辛。以通阳气。姜附之辛。以散阴寒。
琥按上注云。肾苦燥。急食辛以润之。盖少阴下利。非苦燥。方中药味皆用辛者。乃辛以散之。殊非润之之义。
内台方议云。少阴者。肾水也。若脉沉微下利。无热证者。乃少阴客寒不能制肾水。故自利也。以附子为君。
温经散寒。加干姜之辛热。温中益阳。加葱白之辛。通阳气也。以此三味之剂。而治下利。若非内寒阴胜者。不可
用也。
琥按上议云。少阴客寒。不能制肾水。此言实本成注之意。然成注云不能制水。乃肠胃中之水也。若云肾水。
彼下利之水。岂肾水邪。何悖谬之极也。
武陵陈氏云。白通汤者。谓葱白能通阳气。而因名白通也。少阴阳气原微。又为大寒所中。而独见下利一证。
阴盛阳微。其势大危。故用姜附二味。使其从中焦。直达下焦。补益真阳之气而散极寒也。此方与四逆汤相类。独
去甘草。盖驱寒欲其速。辛烈之性。取其骤发。直达下焦。故不欲甘以缓之也。而尤重在葱白。少阴为阴。天之寒
气亦为阴。两阴相合而偏于下利。则与阳气隔绝不通。姜附之力。虽能益阳。不能使真阳之气。必入于阴中。惟葱
白味辛。能通阳气。令阴得阳而利可愈。盖大辛大热之药。原非吾身真阳。不过借以益吾阳气。非有以通之。能令
真阳和会。而何以有济也邪。
或问人身真阳之气何居。余答云。两肾中有真阳之气。乃命门相火也。肺中有真阳之气。乃心与包络之火也。
寒中少阴不独主肾。心家之火亦隔绝也。故用白通汤。以通上下之阳气。
少阴病。下利脉微者。与白通汤。利不止。厥逆无脉干呕烦者。白通加猪胆汁汤主之。服汤。脉暴出者死。微
续者生。（此承上条而言。服白通汤不应。反增无脉等证。少阴病脉原微细。兹但言微者。微为阳虚。即下文无脉
之渐也。下利脉微。与白通汤。非不对病。然服之利不止。厥逆无脉。干呕烦者。寒邪太甚。热药为邪格拒。阳欲
通而不得通。阳气卒不相接而扰乱故也。与白通加猪胆汁汤主之者。内经云。反治之法也。服汤脉暴出者。正气因
发泄而骤脱也。故死。脉微续者。乃真阳之气渐复也。故生。）
Scallion White (four stalks) Dried Ginger (one liang) Aconite Root (one piece, used raw, skin removed, broken into eight pieces)
The above three ingredients. Boil in three sheng of water. Reduce to one sheng. Remove the dregs. Divide into two doses and take warm.
Cheng Wuji's commentary cites the *Neijing* saying: The Kidney dislikes dryness; urgently eat pungent substances to moisten it. The pungency of Scallion White is used to unblock Yang Qi. The pungency of Ginger and Aconite is used to disperse Yin Cold.
Hu notes: The above commentary states "The Kidney dislikes dryness; urgently eat pungent substances to moisten it." Presumably, Shaoyin diarrhea is not a condition of bitter dryness. All herbs in the formula are pungent, which serves to "disperse with pungency," completely contrary to the meaning of "moistening."
*Neitai Fangyi* states: Shaoyin corresponds to Kidney Water. If the pulse is deep and faint with diarrhea, and there are no heat signs, this is because external cold invading Shaoyin cannot control Kidney Water, hence spontaneous diarrhea. Aconite Root is used as the sovereign herb.
To warm the meridians and dispel cold. Add the pungent and hot Dried Ginger to warm the middle and benefit Yang. Add the pungency of Scallion White to unblock Yang Qi. This three-herb formula treats diarrhea. It should not be used unless there is internal cold and excess Yin.
Hu notes: The above discussion states "external cold invading Shaoyin cannot control Kidney Water." This idea actually stems from Cheng's commentary. However, Cheng's statement "cannot control water" refers to water in the intestines and stomach. If one speaks of Kidney Water, how can the water in diarrhea be considered Kidney Water? How extremely erroneous is this.
Chen of Wuling says: Baotong Tang is named so because Scallion White can unblock Yang Qi. The Yang Qi of Shaoyin is originally weak, and having been struck by severe cold, only diarrhea is observed.
Yin is excessive and Yang is weak, creating a critical situation. Therefore, Ginger and Aconite are used to travel directly from the Middle Jiao to the Lower Jiao, tonifying True Yang Qi and dispersing extreme cold. This formula is similar to Sini Tang, except for the removal of Licorice Root. Perhaps to expel cold quickly, the pungent and acrid nature is chosen for its rapid onset to reach the Lower Jiao directly; thus, the sweet flavor that slows action is avoided. The emphasis lies particularly on Scallion White. Shaoyin is Yin, and heavenly cold air is also Yin. When two Yins combine and manifest primarily as diarrhea, Yang Qi becomes isolated and blocked. Although the power of Ginger and Aconite can benefit Yang, they cannot ensure that True Yang Qi enters the Yin. Only Scallion White, being pungent, can unblock Yang Qi, allowing Yin to receive Yang so that diarrhea may cease. Generally, greatly pungent and greatly hot medicines are not originally our body's True Yang; they merely serve to benefit our Yang Qi. Without something to unblock them, enabling the harmonization of True Yang, what help would they be?
Someone asked where the True Yang Qi of the human body resides. I answered: In the two Kidneys resides True Yang Qi, which is the Minister Fire of the Gate of Vitality. In the Lungs resides True Yang Qi, which is the Fire of the Heart and Pericardium.
Cold invading Shaoyin does not solely affect the Kidney; the Fire of the Heart is also isolated. Therefore, Baotong Tang is used to unblock Yang Qi in the upper and lower parts.
In Shaoyin disease, if there is diarrhea with a faint pulse, administer Baotong Tang. If diarrhea persists, with cold limbs, absence of pulse, dry retching, and irritability, Baotong Tang plus Pig Bile is indicated. After taking the decoction, if the pulse suddenly emerges, death ensues. If the pulse gradually returns, life is preserved. (This follows the previous clause. Taking Baotong Tang yields no response, instead adding symptoms like absent pulse. Shaoyin disease pulses are originally fine and faint; here only "faint" is mentioned, indicating Yang deficiency, which is the precursor to the subsequent absent pulse. Diarrhea with a faint pulse treated with Baotong Tang is not incorrect for the disease pattern. However, if after taking it diarrhea persists, with cold limbs, absent pulse, dry retching, and irritability, it is because the Cold pathogen is too severe, and the hot medicine is rejected by the pathogen. Yang desires to unblock but cannot; Yang Qi abruptly fails to connect and becomes chaotic. Hence, Baotong Tang plus Pig Bile is administered, following the *Neijing*'s principle of contrary treatment. If the pulse suddenly emerges after taking the medicine, it indicates righteous Qi suddenly collapsing due to discharge; thus, death. If the pulse gradually returns, it indicates the gradual recovery of True Yang Qi; thus, survival.)