泻血热、滑肠。
甘咸气寒。入厥阴血分。（心包、肝。）凉血活血。利九窍。通二便。（咸寒性滑。）治心
腹邪
气。（即热也。）及痘疮血热毒盛。二便闭涩者。（血热则毒闭、得紫草凉之、则血行而毒出
、曾世荣活幼心书云∶紫草性寒、小儿脾实者可用、脾虚者能作泻、古方惟用茸、取其初得
阳气、以类触类、用发痘疮、今人不达此理、一概用之、误矣。）便滑者勿用。去头须。酒
洗。
泻火补水、润燥滑肠。
辛苦寒滑。泻肾家有余之火。（膀胱邪热、服此亦清。）因而上清肺金。（兼泻胃热。）入
二经
气分。（黄柏入肾经血分、故二药每相须而行。）润肾滋阴。消痰定嗽。止渴除烦。（火入于
肺则烦、泻肾家有余之火、是其本功、至于清金诸效、良由相火不炎、自当驯至也。）安胎
。（能去胎前之热。）治伤寒烦热。蓐劳骨蒸。（退有汗之骨蒸。）利二便。消浮肿。（小便利
则肿消、东垣曰∶热在上焦气分、结秘而渴、乃肺中伏热、不能生水、膀胱绝其化源、宜用
渗湿之药、泻火清金、滋水之化源、热在下焦血分、便秘而不渴、乃真水不足、膀胱干涸、
无阴则阳无以化、宜用黄柏知母、大苦寒之药、滋肾与膀胱之阴、而阳自化、小便自通、丹
溪曰∶小便不通、有热有湿有气结于下、宜清宜燥宜升、又有隔二隔三之治、如肺不燥、
但膀胱热、宜泻膀胱、此正治、如因肺热不能生水、则清肺、此隔二之治、如因脾湿不运、
而精不上升、故肺不能生水、则燥胃健脾。）此隔三之治、（泻膀胱、黄柏知母之类、清肺、
车前茯苓之类、燥脾、二术之类。凡病皆有隔二隔三之治、不独便 也。）伤胃滑肠。
令人作泻。（李士材本草通元药性解曰∶苦寒肃杀、非长养万物者也、世以其滋阴、用治虚
损
上行酒浸，下行盐水拌。忌铁。
泻除血分热邪，润滑肠道。
味甘、咸，气寒。入厥阴经血分。（包括心包络和肝脏。）能凉血并促进血液运行。通畅九窍。通利大小便。（因其味咸性寒且质地滑润。）治疗心腹部由邪气引起的病症。（即热邪。）以及痘疮因血热毒盛导致的大小便闭塞不通者。（血热则毒邪闭阻，得到紫草的清凉作用后，血液运行通畅而毒邪排出。曾世荣在《活幼心书》中说：紫草性寒，小儿脾胃充实者可以使用，若脾胃虚弱者使用会导致腹泻。古方中只使用紫草茸，是取其初得阳气的特性，以类触类，用于发透痘疮。今人不懂这个道理，一概使用，是错误的。）大便滑泄者禁用。去除头部须根。用酒清洗。
泻火补水，滋润干燥，润滑肠道。
味苦、辛，性寒且滑。泻除肾脏多余的火邪。（膀胱中的邪热，服用此药也能清除。）因此向上清肃肺金。（兼有清泻胃热的功效。）进入这两条经脉的气分。（黄柏入肾经血分，所以这两味药常常相互配合使用。）滋润肾脏，滋养阴液。消除痰饮，安定咳嗽。止渴除烦。（火邪侵入肺部则产生烦躁，泻除肾脏多余的火邪是其根本功效，至于清肃肺金的种种疗效，确实是因为相火不炎上，自然逐渐恢复平衡。）安胎。（能清除胎前的热邪。）治疗伤寒引起的烦热。产后虚劳导致的骨蒸潮热。（退去伴有汗出的骨蒸症状。）通利大小便。消除浮肿。（小便通畅则肿胀消退。李东垣说：热邪在上焦气分，结滞便秘且口渴，这是肺中伏热，不能生水，膀胱失去化源，应当使用渗湿的药物，泻火清金，滋补水液的化源；热邪在下焦血分，便秘但不口渴，这是真水不足，膀胱干涸，无阴则阳气无法化生，应当使用黄柏、知母等大苦大寒的药物，滋养肾与膀胱的阴液，阳气自然化生，小便自然通畅。朱丹溪说：小便不通，有因热、有因湿、有因气结于下部的，应当清热、燥湿、升提。又有隔二、隔三的治疗方法，如肺不燥，仅是膀胱热，应当泻膀胱，这是正治法；如果因肺热不能生水，则清肺，这是隔二的治疗法；如果因脾湿不运化，精气不能上升，导致肺不能生水，则燥湿健脾。）这是隔三的治疗方法。（泻膀胱，用黄柏、知母之类；清肺，用车前子、茯苓之类；燥脾，用白术、苍术之类。凡是疾病都有隔二、隔三的治疗方法，不仅仅局限于小便不通的问题。）损伤胃气，润滑肠道。
使人腹泻。（李士材在《本草通元·药性解》中说：苦寒之性肃杀，不是长养万物的性质，世人因为它能滋阴，用来治疗虚损。）
上行时用酒浸泡，下行时用盐水拌炒。忌用铁器。
Drains blood heat, lubricates the intestines.
Sweet and salty in flavor, cold in nature. Enters the Jueyin (Jueyin Meridian) blood level. (Includes Pericardium and Liver.) Cools blood and invigorates blood circulation. Opens the nine orifices. Promotes urination and defecation. (Due to its salty, cold, and slippery nature.) Treats evil qi in the heart and abdomen. (i.e., heat pathogen.) As well as measles/rubella where blood heat and toxin are abundant, causing obstruction of urination and defecation. (Blood heat causes toxin closure; with Zicao's cooling effect, blood circulation improves and toxins are expelled. Zeng Shirong stated in *Huoyou Xinshu*: Zicao is cold in nature; it can be used for children with solid Spleen, but will cause diarrhea in those with deficient Spleen. Ancient formulas only used Zicao tuft, taking advantage of its initial acquisition of Yang Qi, using similarity to trigger similarity, to promote the eruption of measles/rubella. Modern practitioners who do not understand this principle use it indiscriminately, which is a mistake.) Contraindicated in cases of loose stools. Remove the head and rootlets. Wash with wine.
Drains fire and tonifies water, moistens dryness, and lubricates the intestines.
Bitter and pungent in flavor, cold and slippery in nature. Drains the excess fire of the Kidney. (Also clears evil heat from the Bladder.) Thereby ascending to clear Lung Metal. (Also drains Stomach heat.) Enters the Qi level of these two meridians. (Huangbai enters the Kidney meridian blood level, so these two herbs are often used together.) Moistens the Kidney and nourishes Yin. Eliminates phlegm and calms cough. Relieves thirst and removes irritability. (When fire enters the Lung, irritability occurs; draining the excess fire of the Kidney is its fundamental function; the various effects of clearing Metal indeed stem from the fact that when ministerial fire does not flare up, balance is naturally restored.) Calms the fetus. (Can remove heat before childbirth.) Treats vexatious heat caused by Shanghan (Cold Damage). Postpartum consumptive disease with bone-steaming fever. (Reduces bone-steaming fever accompanied by sweating.) Promotes urination and defecation. Reduces edema. (When urination is smooth, swelling subsides. Li Dongyuan said: Heat in the Upper Jiao Qi level, leading to constipation and thirst, is latent heat in the Lung that fails to generate water, causing the Bladder to lose its source. One should use diuretic herbs to drain fire, clear Metal, and nourish the source of water generation. Heat in the Lower Jiao Blood level, leading to constipation without thirst, is insufficient true water and dryness of the Bladder. Without Yin, Yang cannot transform. One should use Huangbai and Zhimu, great bitter and cold herbs, to nourish the Yin of the Kidney and Bladder, allowing Yang to transform naturally and urination to flow freely. Zhu Danxi said: Obstruction of urination can be due to heat, dampness, or Qi stagnation in the Lower Jiao. It should be cleared, dried, or lifted. There are also treatments involving "separated two" and "separated three" principles. If the Lung is not dry but only the Bladder is hot, one should drain the Bladder; this is direct treatment. If the Lung is hot and cannot generate water, one should clear the Lung; this is separated-two treatment. If Spleen dampness fails to transport, preventing essence from ascending and thus the Lung failing to generate water, one should dry dampness and strengthen the Spleen.) This is separated-three treatment. (Draining the Bladder uses herbs like Huangbai and Zhimu; clearing the Lung uses herbs like Qiancao and Fuling; drying the Spleen uses herbs like Baizhu and Cangzhu. All diseases have separated-two and separated-three treatments, not just urinary obstruction.) Damages the Stomach Qi and lubricates the intestines.
Causes diarrhea. (Li Shicai stated in *Bencao Tongyuan · Yaoxingjie*: Bitter and cold properties are austere and killing, not nurturing all things. People use it to treat deficiency because of its ability to nourish Yin.)
For upward action, soak in wine; for downward action, stir-fry with salt water. Avoid iron.