凡泻痢之证，必多口渴，今人但见口渴，即认为火，而不知有火者固能渴，无火者亦能
渴，此不可不辨也。如火盛于中，则熏脾烁胃，津液耗干，故酷好冰水，多而不厌，愈凉愈
快，随饮随消者，此因热而渴，治宜凉也。又如口热作渴，虽欲饮水而饮不能多者，即非真
火，不宜凉也。凡口虽干渴喜凉，而复不喜凉者，是即寒聚于中，而无根之火浮戴于上，此
最忌寒凉者也。然渴有真渴，有似渴。真渴者，必好茶饮，但以喜热、喜凉，即可辨其寒热
。似渴者，干也，非渴也，口虽干而不欲汤饮，则尤非热证可知也。然泻痢之证，因其水泄
于下，必津涸于上，故不免于渴，渴而欲饮，正以内水不足，欲得外水以相济也，岂必皆因
于火乎？诸如此者，必当详审其有火无火，若火有余者，自当清火，水不足者，自当滋阴，
是固然矣。然气为水母，其有气虚不能生水者，不补其母则水不能生，而渴不止也。土为水
主，其有脾虚不能约水者，不强其主则水不能蓄，而渴不止也。使能不治其渴而治其所以渴
，又何渴病之有？
凡泻痢之证，小水必多不利，或多黄赤，此其寒热虚实大有关系，不可不察也。若暴注
之泻，以其清浊不分，水谷并归于大肠，故水有不利者，惟其暂也。若痢疾之小水，则病本
不一，今人但见黄赤不利，无不云其为热，误者多矣。凡因于热者，必其热赤之甚，或多涩
痛，或见鲜血，然必上下皆有热证，方是真热，此宜清凉治之。若非真热，则或以中寒而逼
阳于下者有之，或以泻痢亡阴而水亏色变者有之，或以下焦阳气不暖而水无以化者有之，或
以妄用渗利而 逼干汁者亦有之。但察其三焦无火，则虽黄虽涩，总皆亡阴亡液之证，
不得通以热论，速当培补真阴，乃为良法。《内经》曰∶中气不足，溲便为之变。至哉斯言
，何今人之不能察也？不独此也，每见有小水清白而兼腹痛者，仍用芩连之类，余则不知其
何谓。可恨，可恨。
凡是患有泄泻和痢疾的病人，大多会出现口渴的症状。现在的人一看到口渴，就认为是火邪作祟，却不知道有火邪确实会导致口渴，没有火邪同样也会导致口渴，这一点必须仔细辨别。如果体内热势炽盛，就会熏蒸脾脏、烧灼胃腑，导致津液耗损干枯，因此病人极度喜欢喝冰水，大量饮用也不满足，越凉越觉得爽快，喝下去立刻就能消化，这是因热而导致的口渴，治疗应当使用寒凉药物。又比如口中发热感到口渴，虽然想喝水但喝不下去多少的，这就不是真正的火邪，不适宜用寒凉药物治疗。凡是口虽干渴且喜欢凉的，但又表现出不能耐受寒凉的，这是因为寒气聚集在体内，而无根的火气上浮于上焦，这种情况最忌讳使用寒凉药物。
然而，口渴有真口渴和似口渴之分。真口渴的人，一定喜欢喝茶或饮水，只要通过观察他是喜欢热饮还是冷饮，就可以辨别病证的寒热性质。所谓似口渴，其实是口干，并非真正的口渴，嘴巴虽然干燥但并不想喝水，这更加可以确定不是热证。但是，患泄泻痢疾的病人，因为水分从下部大量流失，必然导致上部津液枯竭，所以难免出现口渴；口渴想要喝水，正是因为体内阴液不足，想要借助外来水分来补充，这哪里一定是因为火邪呢？像这样的情况，必须详细审察是有火还是无火。如果火邪有余，自然应当清火；如果是阴液不足，自然应当滋阴，这当然是正确的道理。然而，气是水的母源，如果有气虚不能化生阴水的情况，不补益其母（气），则阴水无法生成，口渴也就不会停止。土（脾）是水的主宰，如果有脾虚不能约束水液的情况，不强化其主（脾），则水液无法蓄积，口渴也不会停止。如果能不直接治疗口渴，而是治疗导致口渴的原因，那么又怎么会有口渴的病证呢？
凡是患有泄泻痢疾的病人，小便必定多有不利（排尿不畅），或者颜色黄赤，这其中寒热虚实的关系很大，不可不仔细观察。如果是突然发生的剧烈腹泻，由于清浊不分，水谷并归于大肠，所以小便不利只是暂时的。至于痢疾病人的小便，病因并不单一，现在的人一见到小便黄赤不利，无不说是热证，犯错误的人很多。凡是因热邪引起的，必定小便红赤严重，或者伴有涩痛，或者排出鲜血，而且必须上下部位都有热证表现，这才是真正的热证，此时宜用清凉法治疗。如果不是真正的热证，那么有的是因为中焦受寒逼迫阳气下行所致，有的是因为泄泻痢疾损伤阴液导致阴亏而尿色改变所致，有的是因为下焦阳气不温煦导致水液无法正常气化所致，还有的是因为滥用渗湿利水药而逼干了体液所致。只要观察到三焦没有火邪，那么即使小便黄赤、排尿涩滞，总归都是亡阴、亡液的证候，不能一概当作热证论治，应当迅速培补真阴，这才是良策。《内经》说：“中气不足，大小便就会发生异常。”这句话真是精妙啊，为什么现在的人不能明察呢？不只是这一点，我常常见到小便清白却伴有腹痛的病人，医生仍然使用黄芩、黄连等寒凉药物，我真不知道这是什么意思。令人遗憾，令人遗憾。
In cases of diarrhea and dysentery, thirst is commonly present. Nowadays, people often attribute thirst solely to "fire" (heat pathogen), failing to realize that while excess fire can cause thirst, the absence of fire can also lead to it; this distinction must be carefully discerned. If heat is excessive within the middle jiao, it steams the spleen and scorches the stomach, consuming body fluids. Consequently, patients have an intense craving for ice water, drinking large amounts without satiety, finding greater relief with colder temperatures, and digesting it immediately upon ingestion. This type of thirst is caused by heat and should be treated with cooling methods. Conversely, if a patient feels heat in the mouth and desires water but cannot drink much, this is not true fire, and cooling treatments are inappropriate. In cases where the mouth is dry and thirsty, preferring coolness yet unable to tolerate cold, this indicates cold accumulation in the interior with rootless floating fire rising to the upper jiao; such conditions strictly contraindicate the use of cold and cool herbs.
Thirst can be categorized as true thirst or apparent thirst. True thirst involves a desire to drink tea or water; distinguishing between preference for hot or cold drinks allows differentiation between cold and heat patterns. Apparent thirst refers to dryness rather than true thirst; although the mouth is dry, there is no desire to drink, which clearly indicates a non-heat pattern. In diarrhea and dysentery, fluid loss from the lower body leads to depletion of fluids in the upper body, inevitably causing thirst. The desire to drink arises because internal fluids are insufficient and external fluids are needed to replenish them; this is not necessarily due to fire. Such cases require careful examination to determine the presence or absence of fire. If there is excess fire, clearing the fire is appropriate; if there is fluid deficiency, nourishing yin is appropriate. However, qi is the mother of water; if qi deficiency fails to generate water, tonifying the mother (qi) is necessary, otherwise water generation will fail, and thirst will persist. Earth (the Spleen) is the master of water; if spleen deficiency fails to control water retention, strengthening the master (spleen) is required, otherwise water storage will fail, and thirst will continue. By treating the root cause of thirst rather than the symptom itself, the condition of thirst can be resolved.
In cases of diarrhea and dysentery, urination is often difficult or scanty, and may appear yellow or reddish. The relationships among cold, heat, deficiency, and excess are significant and must be observed carefully. In acute violent diarrhea, due to the failure to separate clear from turbid, food and water mix and enter the large intestine, resulting in temporary difficulty in urination. However, regarding urination in dysentery, the etiology varies. Many practitioners assume that yellow and difficult urination always indicates heat, leading to frequent errors. Heat-induced cases typically present with severe redness,涩痛 (astringency and pain), or fresh blood, and crucially, heat signs must be present both above and below to confirm true heat, warranting cooling treatment. If it is not true heat, causes may include: cold in the middle jiao forcing yang downward; yin depletion from prolonged diarrhea/dysentery altering urine color; lack of warming from lower jiao yang qi preventing water transformation; or improper use of diuretics drying up body fluids. If the three jiaos show no fire, even with yellow or astringent urination, these are signs of yin and fluid exhaustion, not heat. Rapid tonification of true yin is the proper method. As stated in the *Neijing*: "Deficiency of central qi leads to abnormalities in urination and defecation." How profound this statement is! Why do modern practitioners fail to observe this? Furthermore, I often see patients with clear, white urine accompanied by abdominal pain who are still prescribed bitter-cold herbs like Huangqin (Scutellariae Radix) and Lianzi (Coptidis Rhizoma). I truly do not understand the rationale behind this. It is regrettable indeed.