火泻，即热泻也。经云∶暴注下迫，皆属于热。暴注者，卒暴注泻也，下迫者，后重里急也。其证泻出
如射，粪出谷道，犹如汤热，肛门焦痛难禁，腹内鸣响而痛，痛一阵，泻一阵，泻复涩滞也，非食泻泻后觉宽
之可比，脉必数至，舌必苔黄，溺必赤涩，口必作渴，此皆火泻之证也。张介宾曰∶热胜则泻，而
小水不利者，以火乘阴分，水道闭塞而然，宜用通利州都法去苍术，加芩、连治之。大概暴注新病者可利，实
热闭涩者可利，形气强壮者可利，小腹胀满者可利，今泄泻属火而不寒，属实
而不虚，故可用通利之法，如久病阴亏者，气虚属寒者，皆不可利，医者不可以不知也。
长夏暑湿之令，有人患泄泻者，每多暑泻也。夫暑热之气，不离乎湿，盖因天之暑热下逼，地之湿热上
腾，人在气交之中，其气即从口鼻而入，直扰中州，脾胃失消运之权，清浊不分，上升精华之气，反下降而为
便泻矣。考暑泻之证，泻出稠粘，小便热赤，脉来濡数，其或沉滑，面垢有汗，口渴喜凉，通体
之热，热似火炎，宜以清凉涤暑法，用却燔蒸，譬如商 飒然倏动，则炎HT 自荡无余矣。如夹湿者，口不甚
渴，当佐木通、泽泻。如湿盛于暑者，宜仿湿泻之法可也。
《内经》云∶湿胜则濡泄，《难经》曰∶湿多成五泄。可见泄泻之病，属湿为多。湿侵于脾，脾失健
运，不能渗化，致HT 门不克泌清别浊，水谷并入大肠而成泄泻矣。湿泻之为病，脉象缓涩而来，泻水而不腹
痛，胸前痞闷，口不作渴，小便黄赤，亦或有腹中微痛，大便稀溏之证。考治湿泻之法，惟念莪先生可
宗，乃曰渗利使湿从小便而去，如农人治涝，导其下流，虽处卑监，不忧巨浸。经曰∶治泻不利小便，非其
治也。若此论之，必当渗利膀胱，宜用通利州都法，则泻自得止矣。
或问曰∶观先生是论，既引《内经》之濡泄，复引《难经》之五泄，何书中不列濡泄之门，又不发五泄
之论，如斯简括，讵无挂漏乎？答曰∶濡泄即洞泄，洞泄之病，已论于前。五泄即胃、脾、大肠、小肠、大瘕
也。考《五十七难》中，胃泄、脾泄，即今之食泻也，大肠泄、小肠泄、大瘕泄，即今之痢疾也。食泻、痢
疾，皆详于后，可弗置论耳。
火泻，就是热泻。医经说：“急骤的腹泻伴有肛门重坠感，都归属于热证。”所谓“暴注”，是指突然剧烈的水样腹泻；所谓“下迫”，是指肛门重坠、里急后重的感觉。其症状表现为泻出物如喷射状，粪便排出肛门时感觉像热水烫一样，肛门焦灼疼痛难以忍受，腹内肠鸣作响且疼痛，痛一阵则泻一阵，泻后仍有涩滞不爽的感觉，这不像食积腹泻那样泻后感到轻松。脉象必定数疾，舌苔必定发黄，小便必定赤涩，口必定口渴，这些都是火泻的症状。张介宾说：“热盛导致腹泻，如果小便不通利，是因为火热侵犯阴分，导致水道闭塞所致，适宜采用通利州都（膀胱）的方法，去掉苍术，加入黄芩、黄连来治疗。”大抵而言，急性发作的新病可以通利，实热闭涩的可以通利，体质强壮的可以通利，小腹胀满的可以通利。现在的泄泻属于火邪而非寒邪，属实证而非虚证，所以可以使用通利的方法。如果是久病导致阴液亏损者，或气虚属寒者，都不可使用通利法，医生不可以不知道这一点。
长夏季节暑湿当令，有人患泄泻的，大多属于暑泻。暑热之气，离不开湿气，这是因为天上的暑热向下逼迫，地上的湿热向上蒸腾，人处于天地气交之中，邪气从口鼻进入，直接扰乱中焦脾胃，使脾胃失去消化运化的功能，清浊不分，上升的精华之气反而下降成为便泻。考察暑泻的症状，泻出物稠粘，小便热赤，脉象濡数，或者沉滑，面色垢浊且有汗，口渴喜欢冷饮，全身发热，热势如火焰燃烧，适宜用清凉涤暑法，以消除燔蒸之热，就像商风飒然吹动，炎暑自然荡然无余。如果夹有湿邪，口不十分渴，应当辅助木通、泽泻。如果湿邪盛于暑邪，适宜仿照湿泻的治疗方法即可。
《内经》说：“湿胜则导致濡泄”，《难经》说：“湿气多形成五种泄泻”。可见泄泻这种病，多由湿邪引起。湿气侵袭脾脏，脾脏失去健运功能，不能渗化水湿，导致大肠门户不能分清别浊，水谷混杂进入大肠而成泄泻。湿泻这种病，脉象缓涩而来，泻下水样便而不腹痛，胸前痞闷，口不渴，小便黄赤，或者也有腹中微痛、大便稀溏的症状。考察治疗湿泻的方法，只有念莪先生的观点值得遵循，他说：“通过渗利使湿气从小便排出，就像农民治理涝灾，疏导下游水流，即使身处低洼之地，也不必担心大水淹没。”医经说：“治疗泄泻如果不通利小便，就不是正确的治法。”按照这个理论，必须渗利膀胱，适宜使用通利州都（膀胱）的方法，那么泄泻自然得以停止。
有人问：“看先生这篇论述，既引用了《内经》的濡泄，又引用了《难经》的五泄，为什么书中不单独列出濡泄的门类，又不详细阐述五泄的理论，如此简括，难道没有遗漏吗？”回答说：“濡泄就是洞泄，洞泄的病，已经在前面论述过了。五泄即胃泄、脾泄、大肠泄、小肠泄、大瘕泄。考察《五十七难》，胃泄、脾泄，就是现在的食积腹泻；大肠泄、小肠泄、大瘕泄，就是现在的痢疾。食积腹泻和痢疾，都在后面详细论述，所以这里就不必赘述了。”
Fire diarrhea, also known as heat diarrhea. The Classics state: "Sudden and violent diarrhea with tenesmus all belong to heat." "Sudden and violent" refers to abrupt and severe watery diarrhea; "tenesmus" refers to the sensation of rectal heaviness and urgency. The symptoms include stool being expelled like a jet, the anus feeling scalded by hot water, burning pain in the anus that is difficult to endure, borborygmus and pain in the abdomen, where pain occurs in waves followed by diarrhea, and a lingering sense of incomplete evacuation after defecation. This cannot be compared to food stagnation diarrhea, where relief is felt after defecation. The pulse must be rapid, the tongue coating yellow, urination red and scanty or painful, and thirst present. These are all signs of fire diarrhea. Zhang Jiebin stated: "Heat excess causes diarrhea; if urination is obstructed, it is because fire invades the Yin aspect, causing blockage of the water passages. It is appropriate to use the method of promoting diuresis via the Zhou Du (bladder), removing Cang Zhu (Atractylodis Rhizoma), and adding Huang Qin (Scutellariae Radix) and Lian Zi (Coptidis Rhizoma) for treatment." Generally speaking, acute onset new diseases can be treated with purgation/diuresis, excess-heat with obstruction can be treated with purgation/diuresis, those with strong constitution can be treated with purgation/diuresis, and those with lower abdominal distension can be treated with purgation/diuresis. Current diarrhea belonging to fire rather than cold, and excess rather than deficiency, can thus use methods of promoting diuresis. However, for those with chronic illness leading to Yin deficiency, or Qi deficiency with cold nature, diuretic methods must not be used; physicians must be aware of this.
During the late summer season when dampness and heat prevail, many cases of diarrhea are due to summerheat diarrhea. Summerheat qi is inseparable from dampness, as heavenly summerheat presses downward and earthly damp-heat rises upward. Humans exist within the intersection of these two qi, so the pathogen enters through the mouth and nose, directly disturbing the Middle Jiao (spleen and stomach). The spleen and stomach lose their functions of digestion and transportation, failing to separate the clear from the turbid. Instead of ascending, the essence qi descends and becomes diarrheal stool. Examining the signs of summerheat diarrhea: stool is thick and sticky, urine is hot and red, the pulse is soggy and rapid or deep and slippery, the face appears greasy with sweating, there is thirst with a preference for cool drinks, and the whole body feels hot, resembling blazing fire. It is appropriate to use Qing Liang Di Shu Fang (Cooling and Clearing Summerheat Decoction) to eliminate the scorching heat, just as a gentle breeze blows suddenly, causing the intense heat to dissipate completely. If accompanied by dampness, with little thirst, Mu Tong (Akebiae Caulis) and Ze Xie (Alismatis Rhizoma) should be added. If dampness exceeds summerheat, one may follow the treatment principles for damp diarrhea.
The Neijing states: "Excess dampness leads to Ru Xie (damp diarrhea)." The Nanjing states: "Dampness often results in five types of diarrhea." This shows that diarrhea is mostly caused by dampness. Dampness invades the Spleen, causing the Spleen to lose its robust transportation function and fail to transform and transport fluids. Consequently, the Large Intestine fails to separate the clear from the turbid, allowing water and grain to mix and enter the Large Intestine, resulting in diarrhea. The signs of damp diarrhea include a slow and choppy pulse, watery stool without abdominal pain, chest oppression, no thirst, yellow-red urine, or possibly slight abdominal pain and loose stools. Regarding the treatment of damp diarrhea, only the views of Mr. Nian E are worthy of following. He said: "Promote diuresis to allow dampness to exit via the urine, similar to how farmers manage floodwaters by guiding them downstream; even in low-lying areas, one need not fear inundation." The Classics state: "Treating diarrhea without promoting diuresis is not the correct method." Based on this theory, one must promote diuresis in the Bladder. Using the method of promoting diuresis via the Zhou Du (bladder) will naturally stop the diarrhea.
A question was asked: "Observing your discussion, you cite Ru Xie from the Neijing and the Five Diarrheas from the Nanjing. Why does the book not list a separate category for Ru Xie, nor elaborate on the Five Diarrheas? Is such brevity an omission?" The answer is: "Ru Xie is synonymous with Dong Xie (cavity diarrhea), which has already been discussed previously. The Five Diarrheas refer to Wei Xie (Stomach diarrhea), Pi Xie (Spleen diarrhea), Da Chang Xie (Large Intestine diarrhea), Xiao Chang Xie (Small Intestine diarrhea), and Da Jia Xie (large mass diarrhea). Examining the Fifty-Seventh Difficulty, Wei Xie and Pi Xie correspond to current Shi Xie (food stagnation diarrhea); Da Chang Xie, Xiao Chang Xie, and Da Jia Xie correspond to current Li Ji (dysentery). Since Shi Xie and Li Ji are detailed later in the text, there is no need to discuss them here."