《内经》曰∶下利发热者死,此论其常也。仲景曰∶下利手足不逆冷,反发热者不死,此论其暴也。盖暴病有阳则
生,无阳则死。故虚寒下利,手足不逆冷,反发热者,或其人藏中真阳未漓,或得温补药后,其阳随返,皆是美征。此
但可收拾其阳,协和其阴,若虑其发热,反如常法行清解之药,鲜有不杀人者矣。
仲景曰∶下利手足厥冷,无脉者,灸之不温,若脉不还,反微喘者死。
手之三阳起于手,足之三阴起于足,故手足为诸阳之本,而脉又为气血之先。平人气动其息,血充其形,出阳入阴,
互为其根。若阴寒极盛,则阳气不布于经脉,五液不行,聚而下利,其脉则无,其手足则冷,去生远矣。此时药不能及,
姑灸之以艾,试其人阳气之存否?若微阳未绝,得艾气之接引。重布经脉,手足转温,随用温经回阳药以继之。若无根
之阳,反从艾火逆奔为喘,则阳从上脱,不复返矣。吁嗟!万物触阳舒之暖而生,触阴惨之寒而杀。世人戕贼其阳,犹
或诿为不知,医操活人之术,乃戕贼夫人之阳,以促人之亡者,岂亦诿之不知耶?
仲景又曰∶下利有微热而渴,脉弱者今自愈。
上条昌会仲景意云∶灸后手足转温,随用温经回阳药以继之。今观此条不药自愈之证,其奥妙愈推愈广。盖重纬下
利脉沉弦者下重,脉大者为未止,脉微弱数者为欲自止,虽发热不死之文,而致其精耳。彼脉微弱而数,利欲自止,但
得不死耳,病未除也。此独言脉弱,乃阴退阳复,在表作微热,在里作微渴,表里之间,微有不和,不治自愈,治之必
反不愈矣。仲景凡吃紧叮咛处,俱金针未度。今僭明之,盖外感证,在表则发热,在里则作渴,不但微热不可尽去,即
作渴亦有不同。如少阴病,五六日自利而渴,其小便白者,则不为里热而为肾虚引水自救。设以里热之渴治之,宁不杀
人乎?昌故会仲景意云∶不治自愈,治之必反不愈,谓夫虑周千变之医,世难轻觏耳。
仲景又云∶下利脉数而渴者,今自愈。设不瘥,必圊脓血,以有热故也。
此一条病机,不但治伤寒病为扼要,即治阴病,最宜消息。盖下利而本之阳虚阴盛,得至脉数而渴,是始焉阴盛。
今则阳复矣,故自愈也。设不愈,则不但阳复,必其阳转胜夫阴,而圊脓血也。五运六气,有胜必有复,《内经》谓
无赞其复,是谓至治,可见复则必有过甚之害。夫既复矣,而重赞之欲何求耶?治阴病者,其阳已复而重赞之,宁不亢
而有悔哉?
仲景又云∶下利脉沉而迟,其人面少赤,身有微热,下利清谷者,必郁冒汗出而解,病患必微热。所以然者,其面
戴阳,下虚故也。
太阳阳明并病,面色缘缘正赤者,为阳气拂郁在表,宜解其表。此之下利脉沉迟,而面见小赤,身见微热,乃阴寒
格阳于外,则身微热。格阳于上,则面小赤。仲景以为下虚者,谓下无其阳,而反在外在上,故云虚也。虚阳至于外越
上出,危候已彰,或其人阳尚有根,或服温药以胜阴助阳,阳得复返而与阴争,瘥可恃以无恐,盖阳返虽阴不能格。然
阴尚盛,亦未肯降,必郁冒少顷,然后阳胜而阴出为汗。阴出为汗,邪从外解,自不下利矣。郁冒汗出,俨有龙战于野,
其血玄黄之象,阳入阴出,从危转安。其机之可畏尚若此,谁谓阴邪可听其盛耶?
仲景又云∶下利后,脉绝,手足厥冷, 时脉还,手足温者生,脉不还者死。
脉绝不惟无其阳,亦无其阴,阳气破散,岂得阴气不消亡乎? 时脉还,乃脉之伏者复出耳,脉岂有一息之不续耶?
仲景用灸法,正所以通阳气,而观其脉之绝与伏耳。故其方即名通脉四逆汤,服后利止。而脉仍不出,是药已大应,其
非脉绝可知,又加人参以补其亡血,斯脉自出矣。成法具在,宜究心焉。
《黄帝内经》说:下利(腹泻)伴有发热的,预后不良,这是论述一般情况。张仲景说:下利手足不逆冷,反而发热的,不会死亡,这是论述突发急症的情况。大概突发疾病中,有阳气则生,无阳气则死。所以虚寒性下利,手足不逆冷,反而发热,或者是患者体内真阳尚未耗散,或者是服用温补药物后,阳气随之恢复,这都是好的征兆。此时只需收敛其阳,调和其阴,如果担心其发热,反而按照常规方法使用清热解表药物,很少有不误杀人的了。
张仲景说:下利手足厥冷,没有脉搏的,施灸后手脚仍不温暖,如果脉搏不恢复,反而出现轻微喘息的,预后不良。
手部的三条阳经起于手部,足部的三条阴经起于足部,所以手足是诸阳经的根本,而脉象又是气血运行的先导。普通人呼吸之间气机运动,血液充盈形体,阳气外出,阴气内入,互为根本。如果阴寒极盛,则阳气不能布达于经脉,津液运行不畅,聚积而下注为下利,此时脉象微弱或消失,手足寒冷,离生机已经很远了。此时药物难以奏效,暂且用艾草施灸,以试探患者阳气是否尚存?如果微弱的阳气未绝,借助艾火的接引,重新布达于经脉,手足转暖,随后再用温经回阳的药物接续治疗。如果是无根之阳,反而随着艾火的热力逆乱上奔导致喘息,那么阳气从上焦脱失,就不再能返回了。唉!万物接触阳气的温暖则舒展生长,接触阴气的惨烈寒冷则枯萎死亡。世人残害自己的阳气,或许可以推托为不知晓,医生掌握救活人的技术,却残害他人的阳气,加速他人的死亡,难道也是推托为不知晓吗?
张仲景又说:下利伴有轻微发热和口渴,脉象弱小的,现在将要自愈。
上文我领会张仲景的意思说:施灸后手足转暖,随即用温经回阳的药物接续治疗。现在看这条条文关于不服药自愈的证候,其中的奥妙越推究越广博。大概重纬(此处指对脉象的辨析)指出:下利脉象沉弦的是里急后重,脉象大的是病未停止,脉象微弱而数的是想要自行停止,虽然提到发热但不死的文句,但这里精微之处在于:那些脉象微弱而数,下利想要自行停止,只是不死罢了,病并未消除。这里唯独说脉弱,乃是阴邪退去、阳气恢复,在体表表现为轻微发热,在体内表现为轻微口渴,表里之间,仅有轻微的不和,不治也能自愈,如果强行治疗反而不能痊愈了。张仲景凡是关键叮咛之处,都如同金针未度般含蓄。现在我僭越阐明它,大概外感病证,在表则发热,在里则作渴,不仅仅是轻微发热不可完全去除,就是作渴也有不同。如少阴病,五六天自利而口渴,如果小便色白,则不是因为里有热,而是因为肾虚引水自救。如果用治里有热的方法治疗这种口渴,岂不是要误杀人吗?所以我领会张仲景的意思说:不治自愈,治之必反不愈,是说那些考虑周全、应对千变万化的医生,世间很难轻易遇到啊。
张仲景又说:下利脉象数而且口渴的,现在将要自愈。如果不痊愈,必定排脓血,因为有热的缘故。
这一条的病机,不仅是治疗伤寒病的要害,即使是治疗阴寒病,也最宜仔细斟酌。大概下利本源于阳虚阴盛,得到脉数而渴的结果,是因为起初阴盛,现在阳气恢复了,所以自愈。假设不愈,则不仅仅是阳气恢复,必然是阳气转而胜过阴气,从而导致排脓血。五运六气理论中,有胜气必有复气,《黄帝内经》说不要助长复气,这称为最高明的治疗,可见复气必然有过甚的危害。既然已经复气了,如果再助长它想求得什么呢?治疗阴寒病的人,其阳气已经恢复却再助长它,难道不是亢盛而有悔恨吗?
张仲景又说:下利脉象沉而迟,病人面部少许发红,身体有轻微发热,下利完谷不化的,必定会出现郁冒(头晕目眩如物蒙蔽)出汗而病解,病人必定有轻微发热。之所以这样,是因为他的面戴阳(面色泛红如妆),下部虚寒的缘故。
太阳病与阳明病合病,面色持续正红的,是阳气拂郁在体表,应当解表。这里的下利脉沉迟,而面部见少许赤色,身体见轻微发热,乃是阴寒格拒阳气于外,所以身体轻微发热。格拒阳气于上,所以面部少许赤色。张仲景认为是下虚,是指下部没有阳气,反而在外在上,所以说虚。虚阳至于外越上出,危重征候已经显露,或者患者阳气尚有根基,或者服用温药以战胜阴寒、辅助阳气,阳气得以回复并与阴气相争,康复可以依靠而不必恐惧,大概阳气回复后,阴寒虽盛也不能再格拒。然而阴气尚盛,也不肯下降,必定郁冒片刻,然后阳气胜而阴气化为汗排出。阴气化为汗排出,邪气从体表解除,自然不下利了。郁冒出汗,俨然有龙战于野、其血玄黄(比喻阴阳剧烈交争)的景象,阳气入内,阴气出外,从危重转为平安。其中的机理可怕尚且如此,谁说阴邪可以听任它强盛呢?
张仲景又说:下利之后,脉搏消失,手足厥冷,偶尔脉搏恢复,手足温暖的会生还,脉搏不恢复的会死亡。
脉搏消失不仅是没有阳气,也没有阴气,阳气破散,难道阴气不随之消亡吗?偶尔脉搏恢复,乃是潜伏的脉象重新出现罢了,脉搏难道有一息都不连续的吗?张仲景使用灸法,正是为了通调阳气,并观察脉搏是断绝还是伏匿。所以他的方剂名叫通脉四逆汤,服用后下利停止。而脉搏仍然不出,说明药物已经大显效力,这就知道并非真正的脉搏断绝,再加人参以补益亡失的血气,脉搏自然就会出现了。成法具在,应当用心研究。
The *Huangdi Neijing* (Yellow Emperor's Inner Canon) states: "Diarrhea accompanied by fever indicates a fatal outcome." This discusses the general rule. Zhang Zhongjing states: "In diarrhea, if the hands and feet are not cold, but rather there is fever, death will not occur." This discusses acute conditions. Generally, in sudden diseases, the presence of Yang Qi leads to life, while its absence leads to death. Therefore, in deficiency-cold diarrhea, if the hands and feet are not cold, but there is fever, it may be that the patient's True Yang (Zhen Yang, the fundamental Yang energy of the body) has not yet dissipated, or that after taking warming and tonifying herbs, Yang Qi returns. These are both auspicious signs. At this time, one should only gather the Yang and harmonize the Yin. If one worries about the fever and instead follows routine methods using clearing and resolving herbs, few will not cause death.
Zhang Zhongjing states: "In diarrhea, if the hands and feet are cold and there is no pulse, moxibustion fails to warm them, and if the pulse does not return, but slight panting occurs, death ensues."
The three Yang meridians of the hand originate from the hands, and the three Yin meridians of the foot originate from the feet; thus, the hands and feet are the root of all Yang meridians, and the pulse is the precursor of Qi and Blood. In a healthy person, movement during respiration circulates Qi, blood fills the form, Yang exits and Yin enters, each serving as the root of the other. If Yin-Cold is extremely excessive, Yang Qi cannot distribute through the meridians, body fluids fail to circulate, accumulate and flow downward causing diarrhea, the pulse becomes absent, and the hands and feet become cold, moving far away from life. At this stage, medicinal herbs cannot reach the disease site; temporarily, moxibustion with mugwort (Ai Ye, 艾叶) should be used to test whether the patient's Yang Qi still exists? If slight Yang has not perished, guided by the warmth of moxa, it can redistribute through the meridians, and the hands and feet turn warm. Subsequently, warming-meridian and returning-Yang herbs should be administered to continue treatment. If it is rootless Yang, it may instead rush upward reversely due to the fire of moxa, causing panting; then Yang escapes from the upper jiao and will not return. Alas! All things touch the warmth of Yang to expand and grow, and touch the chill of Yin to wither and die. People harm their own Yang, perhaps excusing themselves as ignorant; doctors possess the art of saving lives, yet they harm others' Yang, hastening their death. Do they also excuse themselves as ignorant?
Zhang Zhongjing further states: "In diarrhea, with slight fever and thirst, and a weak pulse, recovery will occur spontaneously."
In the previous section, I interpreted Zhang Zhongjing's intent: after moxibustion, when the hands and feet turn warm, one should immediately follow up with warming-meridian and returning-Yang herbs. Observing this clause regarding spontaneous recovery without medication, its subtlety becomes broader upon deeper analysis. Regarding pulse differentiation: in diarrhea, a deep-choppy pulse indicates tenesmus; a large pulse indicates the disease has not ceased; a weak-and-rapid pulse indicates it is about to stop spontaneously. Although the text mentions fever but not death, the essence here is precise: those with weak-and-rapid pulses whose diarrhea is about to stop merely avoid death; the disease is not eliminated. Here, it specifically mentions a weak pulse, indicating Yin receding and Yang recovering. Externally, this manifests as slight fever; internally, as slight thirst. Between the exterior and interior, there is only slight disharmony; it heals spontaneously without treatment, and treating it would likely prevent recovery. Wherever Zhang Zhongjing emphasizes crucial points, he remains implicit like a golden needle not yet passed. Now I presume to clarify it: generally, in exogenous patterns, exterior involvement causes fever, interior involvement causes thirst. Not only should slight fever not be completely eradicated, but thirst also varies. For instance, in Shaoyin disease, spontaneous diarrhea with thirst for five to six days, if the urine is white, it is not due to interior heat, but because Kidney Deficiency draws water to save itself. If one treats this thirst as interior heat, would it not kill the patient? Thus, I interpret Zhang Zhongjing's intent: "Heals spontaneously without treatment; treatment leads to non-recovery," referring to physicians who consider all variables and adapt to thousands of changes, which are rare in the world.
Zhang Zhongjing further states: "In diarrhea, if the pulse is rapid and there is thirst, recovery will occur spontaneously. If it does not heal, pus and blood will appear in the stool, due to the presence of Heat."
The pathogenesis of this clause is not only key to treating Taiyang disease, but also requires careful consideration when treating Yin diseases. Diarrhea originating from Yang deficiency and Yin excess, presenting with a rapid pulse and thirst, indicates that although initially Yin was excessive, Yang has now recovered, hence spontaneous recovery. If it does not heal, it implies not just Yang recovery, but Yang overcoming Yin excessively, leading to pus and blood in the stool. In the theory of Five Movements and Six Qi, an excess force is followed by a counteracting force. The *Neijing* states, "Do not assist the counteraction," which is considered supreme treatment. This shows that counteraction inevitably brings excessive harm. Since counteraction has already occurred, what is sought by assisting it again? In treating Yin diseases, if Yang has already recovered and one assists it again, is it not inviting hyperactivity and regret?
Zhang Zhongjing further states: "In diarrhea, if the pulse is deep and slow, the patient's face shows slight redness, the body has slight fever, and the stool contains undigested food, there will inevitably be vertigo/dizziness (Yu Mao, 郁冒), sweating, and resolution. The patient must have slight fever. The reason is 'Face Floating Yang' (Dai Yang, 戴阳) due to lower deficiency."
When Taiyang and Yangming diseases combine, a continuous bright red face indicates Yang Qi stagnation in the exterior, requiring exterior release. Here, in diarrhea with a deep-slow pulse, slight facial redness, and slight body fever, it is Yin-Cold repelling Yang outward, causing slight body fever. Repelling Yang upward causes slight facial redness. Zhang Zhongjing attributes this to lower deficiency, meaning Yang is absent below, yet appears above and outside, hence termed deficiency. When deficient Yang floats outward and upward, critical signs are evident. If the patient's Yang still has roots, or if warming herbs are taken to overcome Yin and assist Yang, Yang returns and contends with Yin; recovery can be expected without fear. Once Yang returns, Yin cannot repel it. However, since Yin is still excessive and unwilling to descend, there will be brief vertigo/dizziness, after which Yang overcomes Yin, and Yin transforms into sweat. Yin exiting as sweat means pathogens resolve from the exterior, and diarrhea naturally stops. Vertigo/dizziness and sweating resemble the image of dragons fighting in the wild, with black and yellow blood, symbolizing Yang entering and Yin exiting, turning from critical to safe. The mechanism is so formidable; who says Yin pathogens can be allowed to flourish?
Zhang Zhongjing further states: "After diarrhea, if the pulse is absent and the hands and feet are cold, but occasionally the pulse returns and the hands and feet become warm, life is preserved; if the pulse does not return, death ensues."
An absent pulse indicates not only the absence of Yang, but also the absence of Yin. If Yang Qi is scattered, how can Yin Qi not perish? Occasional pulse return means the hidden pulse re-emerges; does the pulse ever cease for even a breath? Zhang Zhongjing uses moxibustion precisely to unblock Yang Qi and observe whether the pulse is absent or hidden. Hence, his formula is named Tongmai Sini Tang (Pulse-Returning Decoction). After administration, diarrhea stops. If the pulse still does not emerge, it indicates the medicine has had a major effect, proving it was not true pulse absence. Adding Ren Shen (Ginseng Radix) to replenish lost blood allows the pulse to emerge naturally. Established methods are present; one should study them carefully.