（古文作利，今文作痢。）
夫利有三因∶因于外感风寒暑湿，而为下利脓血者，有死有生，有气有血，宜补宜泻，宜寒宜热，具
在《伤寒论》、《金匮要略》及《千金》诸方，各宜随证而分别治之。又有阳中雾露之气，阴中混浊之邪，
血凝自下，状如豚肝，阴阳俱厥，脾气孤弱，五液注
下，下焦不阖，清便下重，令便数难，脐筑湫痛，命将难全，详论《辨脉篇》中。此外因之下利也。有因
食饮不节，起居不时，阴受之而入五脏，则填满闭塞，下为飧泄，久为肠 ，此内因之下利也。有因于
奇恒之下利者，乃三阳并至，三阴莫当，积并则为惊，病起疾风，至如霹雳，九窍皆塞，阳气滂溢，干
嗌喉塞，并于阴则上下无常，薄为肠 ，其脉缓小沉涩，血温身热死，热见七日死。盖因阳气偏剧，阴气
受伤，是以脉小沉涩。此证急宜大承气汤泻阳养阴，缓则遂成不救。医者不知奇恒之因，见脉气和缓，而用
平易之剂，又何异于毒药乎？予故曰∶服平和汤而愈者，原不死之病，勿药亦可；服平和汤而后成不救者，医之罪也。
夫邪之中于人也，有皮肉筋骨腑脏之浅深，有阴阳寒热燥湿之气化。况风之善行而数变，是以伤于皮
毛，则为头痛、发热、咳嗽、鼽涕之轻证；入于血脉，则肌肤不仁，或为疠疡，或为肿 ；邪在肌肉筋
骨，则为痛痹，或为拘挛，或为偏枯，邪入于腹，或为飧泄，或为燥结；邪入于腑，即不识人；邪入于脏，
舌即难言，口唾痰涎。此邪入之有浅深，而病之有死生轻重也。夫天有六淫之邪，风有六气之化。邪袭于
阳，则为热化；中于阴，则为阴寒。湿盛者，则痰涎上壅；燥盛者，则肠胃下结。邪气盛者，则病气形气
皆盛；正气虚者，则病气形气皆虚。总属天之风邪，而人身中有寒、热、燥、湿、虚、实之化。是以河间
谓中风主于火，丹溪谓主于痰，东垣谓主于气，又曰∶中风之病，惟年老者有之。此皆未明阴阳气化之
道也。夫 僻拘挛，目斜不语，在童稚则为急慢惊风，在少壮则为中风卒暴。予一侄女，年二十余、体
甚丰浓，精神强旺，六月盛暑，恒贪风凉，临窗露卧。忽一日头大痛，身热，无汗，口不渴而躁，手足
拘急，口眼 斜。余诊之，六脉沉细。予曰∶邪已入脏，此危证也。次日即不能言，口唾涎，药亦不受，
病三日而死。如此之候，年少壮盛者比比，又非独于老人也。经曰∶夏伤于暑，冬伤于寒。是夏月止有风
暑，而无寒邪，即见阴寒之证，而宜于姜、附之热药者，乃邪中于里阴而不得阳热之化，非天之寒气也。
（夏月阳气尽发越于外，而里气虚寒。）时下名流，咸以此证为中
寒。予微哂之曰∶是固知年少之无中风也。若谓少壮之人，血气充实，而不为风邪所中，是亦不应中
寒、中暑矣。此习俗之固弊，牢不可破者也。或曰∶然则老年之多中风者，何气使然？曰∶年老之人，天癸已
绝，血气虚衰，腠理不密，故易于受风，且精气竭而痰火盛，是以有因痰、因火、因气之说焉。夫客气邪
风，中人多死。若五脏安和，元真通畅，不使形体有衰，病则无由入其腠理。《灵枢经》曰∶八风之邪，皆
从其虚之乡来，乃能病患。三虚相搏，则为暴病卒死。两实一虚，则为淋露寒热。其有三虚而偏中于邪风，则
为击仆偏枯。故圣人避风，如避矢石。是圣人之教化，又何尝有年老少壮之分也！
（古文中的“利”字，今文写作“痢”。）
下利有三种病因：因感受外感的风寒暑湿邪气，导致出现下利脓血症状的，病情有死有生，病位涉及气分或血分，治疗宜用补法或泻法，宜用寒药或热药，这些内容详细记载在《伤寒论》、《金匮要略》以及《千金方》等著作中，医生应当根据具体证候分别进行治疗。又有因阳气遭受雾露之气侵袭，阴气遭受混浊邪气侵袭，导致血液凝滞而下泄，血色状如猪肝，阴阳之气均发生厥逆，脾气孤立虚弱，五脏津液注注下泄，下焦门户不能闭合，大便清稀且伴有重坠感，导致排便次数多而困难，脐腹部筑动作痛且疼痛轻微如水浸之痛，生命难以保全，详细论述见《辨脉篇》中。这是由外因引起的下利。有因饮食不节制，起居没有规律，邪气从阴分侵入并进入五脏，导致脏腑充满闭塞，向下发展为完谷不化的飧泄，日久则形成肠澼（痢疾），这是由内因引起的下利。还有属于奇恒之变的下利，乃是三阳经邪气并至，三阴经无法抵挡，积滞并盛则引发惊骇，发病急骤如狂风，来势迅猛如霹雳，九窍全部闭塞，阳气滂溢泛滥，咽喉干燥阻塞，若邪气并入阴分则上下无常，迫及肠道则形成肠澼，其脉象缓小沉涩，若血液温热且身体发热则为死证，若发热持续七日亦为死证。这是因为阳气偏盛剧烈，阴气受到损伤，所以脉象表现为小、沉、涩。此证急需使用大承气汤泻除阳热以滋养阴液，若拖延则会导致无法救治。医生如果不知道奇恒之变的病因，见到脉气和缓，就使用平和的药剂，这与使用毒药有什么区别呢？所以我常说：服用平和汤而痊愈的，原本就是不会致死的疾病，不吃药也可以；服用平和汤后反而导致无法救治的，是医生的罪过。
邪气侵犯人体，有皮肉筋骨脏腑的浅深区别，也有阴阳寒热燥湿的气化差异。况且风邪善于行走且变化迅速，所以伤于皮毛，则表现为头痛、发热、咳嗽、鼻塞流涕等轻证；侵入血脉，则肌肤麻木不仁，或者成为疠疡（麻风疮疡），或者发生肿胀；邪气在肌肉筋骨，则成为痛痹，或者发生拘挛，或者成为偏枯（半身不遂）；邪气进入腹部，或者成为飧泄，或者成为燥结；邪气进入腑，就会神志不清不识人；邪气进入脏，舌头僵硬难以言语，口吐痰涎。这就是邪气入侵有浅深之分，而疾病有生死轻重之别。天有六淫邪气，风有六气气化。邪气侵袭阳分，则化为热证；中于阴分，则化为阴寒证。湿气盛的，则痰涎上壅；燥气盛的，则肠胃下部结滞。邪气盛的，则病气和形气都盛；正气虚的，则病气和形气都虚。总归是天之风邪，而人体内有寒、热、燥、湿、虚、实的气化变化。所以刘河间认为中风主于火，朱丹溪认为主于痰，李东垣认为主于气，又说：中风的病，只有老年人会有。这些都是没有明白阴阳气化道理的缘故。口眼歪斜和拘挛，在儿童时期则是急慢惊风，在青壮年时期则是中风卒暴。我的一个侄女，二十多岁，身体非常丰满浓密，精神强旺，六月盛夏，常常贪图风凉，临窗露天睡觉。忽然有一天头部剧痛，身体发热，无汗，口不渴但烦躁，手足拘急，口眼歪斜。我诊察她的脉象，六脉沉细。我说：邪气已经入脏，这是危重的证候。第二天就不能说话，口吐涎沫，药物也无法受纳，患病三天就死了。像这样的证候，年轻力壮的人比比皆是，并不独见于老人。《内经》说：夏伤于暑，冬伤于寒。夏季只有风暑，而没有寒邪，即使出现阴寒的证候，适宜使用姜、附等热药治疗的，那是邪气中于里阴而不能得到阳热的气化，并非天之寒气。（夏季阳气尽发越于体表，而体内气机虚寒。）时下名流，都将这种证候称为中寒。我微微嘲笑他们说：这固然知道年轻人不会得中风。如果说年少体壮之人，血气充实，而不被风邪所中，这也是不应该中寒、中暑的。这是习俗的顽固弊端，牢不可破啊。有人问：那么老年人多患中风，是什么气使然呢？回答说：年老之人，天癸已绝，血气虚衰，腠理不紧密，所以易于受风，而且精气枯竭而痰火旺盛，所以有因痰、因火、因气的说法。客气的邪风，中人往往致死。如果五脏安和，元真通畅，不让形体衰弱，病邪就无法侵入腠理。《灵枢经》说：八风之邪，都是从人体虚弱的地方来的，才能致病。三虚相搏结，就会发生暴病猝死。两实一虚，就会发生淋露寒热。如果有三虚而偏中于邪风，就会发生击仆偏枯。所以圣人避风，如同躲避箭石。圣人的教化，又何尝有老年少壮的区别呢！
(The character "Li" in the ancient text is written as "Di" in the modern text.)
Dysentery (lower abdominal pain with bloody stool) has three causes: those caused by external contraction of Wind, Cold, Summer-heat, and Dampness, resulting in dysentery with pus and blood, may result in death or survival, involve Qi or Blood, and require tonification or purgation, cold or hot treatments. These are detailed in *Shanghan Lun* (Treatise on Cold Damage), *Jingui Yaolue* (Essential Prescriptions from the Golden Cabinet), and various formulas in *Qianjin Fang* (Thousand Gold Formulas); physicians should treat them according to specific patterns. There are also cases where Yang is invaded by mist and dew, and Yin is invaded by turbid pathogens, causing blood coagulation and downward discharge resembling pig liver, with both Yin and Yang Qi experiencing Jue (reversal), isolated and weak Spleen Qi, leakage of the Five Fluids downward, failure of the Lower Jiao to close, clear stool with a sensation of heaviness, frequent but difficult defecation, rumbling and mild pain in the navel area, leading to a life-threatening condition; this is discussed in detail in the *Bian Mai Pian* (Chapter on Pulse Differentiation). This is dysentery caused by external factors. There are also cases caused by irregular diet and improper daily routine, where pathogens enter through the Yin aspect into the Zang organs, causing fullness and blockage, manifesting downward as undigested food diarrhea (Sun Xie), and over time developing into Chang Pi (dysentery/intestinal inflammation); this is dysentery caused by internal factors. There are also atypical forms of dysentery, where the Three Yang meridians arrive simultaneously and cannot be resisted by the Three Yin meridians; accumulation and confluence cause fright, onset is sudden like fierce wind, rapid like thunderbolts, all nine orifices are blocked, Yang Qi overflows excessively, causing dry throat and obstruction, and if pathogens merge with Yin, movement becomes erratic, pressing into the intestines to form Chang Pi. The pulse is slow, small, deep, and choppy; if blood is warm and body temperature is high, it indicates death; if heat persists for seven days, it also indicates death. This is because Yang Qi is excessively vigorous while Yin Qi is injured, hence the pulse is small, deep, and choppy. This condition urgently requires Da Cheng Qi Tang (Major Order the Qi Decoction) to purge Yang and nourish Yin; delay will lead to untreatable conditions. If physicians do not understand the cause of atypical dysentery and, seeing a harmonious pulse, use mild formulas, it is no different from using poison. Therefore, I say: those who recover after taking mild formulas had illnesses that were originally non-fatal and could have recovered without medicine; those who become untreatable after taking mild formulas bear the fault of the physician.
Pathogens invading humans vary in depth among skin, flesh, sinews, bones, Fu, and Zang organs, and differ in their transformation according to Yin-Yang, Cold-Heat, Dryness, and Dampness. Moreover, since Wind moves freely and changes frequently, invasion of skin and hair results in mild symptoms such as headache, fever, cough, and rhinorrhea; invasion of blood vessels leads to insensitivity of skin and flesh, leprosy-like ulcers, or swelling; pathogens in muscles and sinews cause painful Bi syndrome, spasms, or hemiplegia; pathogens entering the abdomen cause Sun Xie or dryness and constipation; pathogens entering the Fu organs cause loss of consciousness; pathogens entering the Zang organs cause stiff tongue and inability to speak, with saliva and phlegm dribbling from the mouth. Thus, the depth of pathogen entry determines the severity and prognosis of the disease. Heaven has Six Excesses (Six Evils); Wind undergoes transformations of Six Qi. Pathogens attacking Yang transform into Heat; those striking Yin transform into Cold-Damp. Excess Dampness causes phlegm-saliva to obstruct upwards; excess Dryness causes binding downwards in the intestines and stomach. When pathogens are strong, both pathological Qi and formative Qi are excessive; when healthy Qi is deficient, both pathological Qi and formative Qi are deficient. Ultimately, these are Heavenly Wind pathogens, but within the human body, they transform into Cold, Heat, Dryness, Dampness, Deficiency, and Excess. Therefore, Liu Hejian stated that stroke is primarily due to Fire; Zhu Danxi stated it is primarily due to Phlegm; Li Dongyuan stated it is primarily due to Qi. It is also said that stroke occurs only in the elderly. All these views fail to understand the Dao of Yin-Yang Qi transformation. Facial deviation and spasms in children constitute Ji Man Jing Feng (Acute and Chronic Convulsions); in young adults, they constitute Stroke (Zhong Feng) with sudden onset. My niece, in her twenties, was very robust and vigorous. In midsummer, she often sought coolness, sleeping by the window exposed to the air. Suddenly, one day she suffered severe headache, fever, anhidrosis, thirstlessness but irritability, limb spasms, and facial deviation. I diagnosed her pulse as deep and fine in all six positions. I said, "The pathogen has entered the Zang organs; this is a critical condition." The next day she became aphasic, dribbled saliva, could not tolerate medication, and died three days later. Such presentations are common among the young and vigorous, not exclusive to the elderly. The Classics state: "Summer injury by Summer-heat, Winter injury by Cold." In summer, there is only Wind and Summer-heat, no Cold pathogen. Even if Cold-damp symptoms appear requiring hot herbs like Ginger (Sheng Jiang) and Aconite (Fu Zi), it is because the pathogen struck the interior Yin without receiving Yang-heat transformation, not due to Heavenly Cold. (In summer, Yang Qi is fully dispersed outward, leaving the interior deficient and cold.) Contemporary scholars mistakenly label this as Zhong Han (Cold Stroke). I smile faintly and say: "You certainly know that the young do not get stroke. But if you claim that young and vigorous people, with abundant Qi and Blood, are immune to Wind pathogens, then they should also be immune to Cold and Summer-heat injuries." This is a stubborn custom, unbreakable. Someone asks: "Then why do the elderly suffer more from stroke?" I reply: "The elderly have exhausted Tian Gui (essence related to reproduction), their Qi and Blood are deficient, their Cou Li (pores/interstices) are loose, making them susceptible to Wind. Moreover, essence is depleted while Phlegm-Fire is rampant, giving rise to theories attributing stroke to Phlegm, Fire, or Qi. Guest pathogens and evil winds can kill upon invasion. If the Five Zang organs are harmonious and Yuan Zhen (original true Qi) flows smoothly, preventing physical decline, pathogens cannot enter the Cou Li. The *Ling Shu Jing* states: 'Eight Winds come from the direction of deficiency, causing disease.' When Three Deficiencies combine, sudden death occurs. With Two Excesses and One Deficiency, dampness and cold-heat disorders occur. With Three Deficiencies and partial strike by Wind, collapse and hemiplegia result. Thus, sages avoid wind as they would arrows and stones. Does sage teaching distinguish between old and young? No!"