半夏（洗味辛温） 桂枝（去皮味辛热） 甘草（炙味甘平以上各等分）
以上三味。各别捣筛已。合治之。白饮和。服方寸匕。日三服。若不能散服者。以
水一升。煎七沸。内散一两方寸匕。更煎三沸。下火。令小冷。少少咽之。
内经曰。寒淫所胜。平以辛热。佐以甘苦。半夏桂枝之辛。以散经寒。甘草之甘。以
缓正气。
少阴病下利。白通汤主之。
少阴主水。少阴客寒。不能制水。故自利也。白通汤温里散寒。
葱白（四茎味辛温） 干姜（一两味辛热） 附子（一枚生用去皮破八片味辛热）
上三味。以水三升。煮取一升。去滓。分温。再服。
内经曰。肾苦燥。急食辛以润之。葱白之辛。以通阳气。干姜附子之辛。以散阴寒。
张兼善云。白通汤。及白通加猪胆汤。真武汤。与通脉四逆汤。皆为少阴下利而设。
除用姜附相同。其余之药各异。何也。盖下阴下利。寒气已甚。非姜附则不能治。然下
利之理无殊。而兼有之证不一。用药故不同耳。
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。
少阴病。下利。脉微为寒极阴胜。与白通汤。复阳散寒。服汤。利不止。厥逆无脉。
干呕烦者。寒气太甚。内为格拒。阳气逆乱也。与白通汤和猪胆汁汤。以和之。内经曰。
逆而从之。从而逆之。又曰。逆者正治。从者反治。此之谓也。服汤脉暴出者。正气因
发泄而脱也。故死。脉微续者。阳气渐复也。故生。
半夏（经过水洗，味辛性温） 桂枝（去掉外皮，味辛性热） 甘草（炙烤，味甘性平，以上三味药分量相等）
这三味药。分别捣碎并筛成细粉后，混合均匀。用米汤调和。每次服用一方寸匕的药量。每天服用三次。如果不能散服的话，用水一升，煮沸七次。将一两方寸匕的药散放入其中，再煮沸三次。撤去火源。待药液稍微变凉。少量多次地咽下。
《内经》说。寒邪过盛时，用辛热之品来平抑它。用甘苦之品作为辅助。半夏和桂枝的辛味，用来发散经络中的寒邪。甘草的甘味，用来缓和正气。
少阴病出现下利的症状，用白通汤主治。
少阴经主司水液代谢。少阴经受客寒侵袭。不能制约水液。所以导致自发性下利。白通汤能温补里阳、驱散寒邪。
葱白（四根，味辛性温） 干姜（一两，味辛性热） 附子（一枚，生用，去掉外皮，破开成八片，味辛性热）
以上三味药。用水三升。煮取一升药液。去除药渣。分两次温服。
《内经》说。肾脏厌恶干燥，急需食用辛味食物来滋润它。葱白的辛味，用来通达阳气。干姜和附子的辛味，用来驱散阴寒。
张兼善说。白通汤，以及白通加猪胆汁汤、真武汤、通脉四逆汤，都是为少阴病下利而设立的。
除了使用姜和附子相同之外，其余的药物各不相同。为什么呢？大概是因为下阴下利，寒气已经非常严重，不用姜和附子就不能治疗。然而下利的机理并无不同，但兼有的证候却不一样。用药因此不同罢了。
少阴病出现下利，脉象微弱的，给予白通汤。如果下利不止，四肢厥冷且无脉搏，干呕心烦的，用白通加猪胆汁汤主治。服药后，如果脉搏突然显现的会死亡，脉搏逐渐恢复的则生存。
少阴病。下利。脉微弱表示寒极阴盛。给予白通汤。回复阳气、驱散寒邪。服药后，下利不止，四肢厥冷且无脉搏，干呕心烦的，这是寒气太甚，体内产生格拒，阳气逆乱。给予白通汤配合猪胆汁汤，以调和它。《内经》说。逆着病势而治，顺着病势而治。又说。逆证用正治法，顺证用反治法。说的就是这种情况。服药后脉搏突然显现的，是因为正气因发泄而脱失。所以死亡。脉搏逐渐恢复的，是阳气渐渐回复。所以生存。
Pinellia Rhizome (washed, acrid and warm) Cinnamon Twig (bark removed, acrid and hot) Licorice Root (roasted, sweet and neutral, equal parts of the above three)
The above three herbs. Each is separately pounded and sifted into powder. They are then mixed together. Mixed with a white drink (rice water). Take one fangcun bi (a square-inch measure) per dose. Three doses daily. If it cannot be taken as a powder, use one sheng (approx. 200ml) of water. Boil seven times. Add one liang (approx. 15-30g) of the powder measured in a fangcun bi. Boil for another three boils. Remove from fire. Let it cool slightly. Swallow slowly in small amounts.
The *Neijing* states: When cold excess prevails, pacify it with acrid and hot substances. Assist with sweet and bitter substances. The acridity of Pinellia Rhizome and Cinnamon Twig disperses channel cold. The sweetness of Licorice Root moderates the righteous qi.
Shaoyin disease presenting with diarrhea is primarily treated with Baitong Decoction.
Shaoyin governs water. Shaoyin is invaded by exogenous cold. It cannot control water. Hence spontaneous diarrhea occurs. Baitong Decoction warms the interior and dispels cold.
Scallion White (four stalks, acrid and warm) Dried Ginger (one liang, acrid and hot) Aconite Lateralis Radix Preparata (one piece, raw, bark removed, broken into eight pieces, acrid and hot)
The above three herbs. With three sheng of water. Boil to obtain one sheng of decoction. Remove dregs. Divide into two warm doses.
The *Neijing* states: The Kidney dislikes dryness; urgently consume acrid foods to moisten it. The acridity of Scallion White unblocks yang qi. The acridity of Dried Ginger and Aconite Lateralis Radix Preparata dispels yin cold.
Zhang Jianshan said: Baitong Decoction, as well as Baitong Zhu Dan Jiang Decoction, Zhenwu Decoction, and Tongmai Sini Decoction, are all established for Shaoyin diarrhea.
Except for the use of Ginger and Aconite being the same, the remaining herbs differ. Why? Presumably because in lower yin diarrhea, cold pathogenic factors are already severe. Without Ginger and Aconite, they cannot be treated. However, the mechanism of diarrhea is not different, but accompanying syndromes vary. Therefore, the medication differs.
Shaoyin disease with diarrhea and a faint pulse is given Baitong Decoction. If diarrhea does not stop, and there is cold extremities, absence of pulse, dry retching, and irritability, Baitong Zhu Dan Jiang Decoction is primarily used. After taking the decoction, if the pulse suddenly emerges, death ensues; if the pulse gradually returns, life is preserved.
Shaoyin disease. Diarrhea. A faint pulse indicates extreme cold and yin excess. Baitong Decoction is given to restore yang and dispel cold. After taking the decoction, if diarrhea does not stop, and there are cold extremities, absence of pulse, dry retching, and irritability, this is due to excessive cold causing internal rejection and chaotic yang qi. Baitong Decoction combined with Pig Bile Decoction is given to harmonize it. The *Neijing* states: Treat against the trend, or follow the trend. It also states: Direct treatment for contrary conditions, reverse treatment for following conditions. This is what is meant. If the pulse suddenly emerges after taking the decoction, it is because righteous qi escapes and collapses due to discharge. Thus, death. If the pulse gradually returns, it is because yang qi is slowly recovering. Thus, life.