大泻，通脏腑水湿
苦寒有毒。能泻脏腑水湿，行血发汗，利大小便。
治十二种水，腹满急痛，积聚症瘕，颈腋痈肿，风毒脚肿，通经堕胎。误服损真气（时
珍曰∶痰涎为物，随气升降，无处不到。入心则迷，成癫痫；入肺则塞窍，为咳喘背冷；入
肝则胁痛干呕，寒热往来；入经络则麻痹疼痛；入筋骨则牵引隐痛；入皮肉则瘰 痈肿。陈
无择并以控涎丹主之，殊有奇效，此乃治痰之本。痰之本，水也，湿也，得气与火。则结为
痰。大戟能泄脏腑水湿，甘遂能行经络水湿，白芥子能散皮里膜外痰气，惟善用者能收奇功
也。又曰∶钱仲阳谓肾为真水，有补无泻。复云痘症变黑归肾者，用百祥膏下之，非泻肾也
，泻其腑，则脏自不实。腑者，膀胱也。百祥惟大戟一味，能行膀腕之水故也。窍谓非独泻
腑，乃肾邪实而泻肝也。实则泻其子，大戟浸水青绿，肝胆之色也。痘症毒盛火炽，则水益
涸，风挟火势，则土受亏，故津液内竭，不能化脓，而成黑陷之证，泻其风火之毒，所以救
肾扶脾也。昂按∶泻心乃所以补心，泻肾即所以救肾，邪热退，则真阴复矣。《机要》用大
戟一两，枣三枚，同煮焙干，去戟，用枣丸服，名枣变百祥丸）。
杭产紫者为上，北产白者伤人。浆水煮，去骨用。得大枣则不损脾。畏菖蒲。反甘草。
其味苦、性寒，有毒。能够攻逐脏腑内的水湿停滞，促进血液运行并引发汗出，通利小便和大便。
用于治疗十二种水肿病证，腹部胀满且急迫疼痛，体内积聚形成的包块（症瘕），颈部和腋下的痈肿，风毒引起的小腿肿胀，以及通经堕胎。如果误服会损伤人体的真气。（李时珍说：痰涎这种病理产物，随着气的升降运动，无处不到。进入心脏则导致神志昏迷，形成癫痫；进入肺部则阻塞窍道，引起咳嗽、气喘和背部发冷；进入肝脏则导致胁肋疼痛、干呕，出现忽冷忽热的症状；进入经络则导致肢体麻木和疼痛；进入筋骨则引起牵引性的隐痛；进入皮肉之间则形成瘰疬和痈肿。陈无择都用控涎丹来主治这些病症，效果奇特，这是治疗痰病的根本方法。痰的根本来源是水湿，遇到气和火的作用，就会凝结成痰。大戟能泄除脏腑的水湿，甘遂能通行经络的水湿，白芥子能消散皮里膜外的痰气，只有善于使用的人才能收到奇效。）又说：钱乙（钱仲阳）认为肾是真水之脏，只宜补不宜泻。但又说痘疹病情变化，黑陷归肾者，用百祥膏攻下它，这并不是泻肾，而是泻其相表里的腑，那么脏气自然就不会壅实。这里的腑指的是膀胱。百祥膏仅由大戟一味药组成，是因为它能行膀胱之水故也。（另有观点认为：不仅仅是泻腑，而是肾邪实证而通过泻肝来治疗。根据“实则泻其子”的理论，大戟浸泡在水中呈青绿色，这是肝胆的颜色。痘疹毒盛火炽，则肾水更加枯竭，风邪挟持火势，则脾土受亏，因此津液在内枯竭，不能化脓，从而形成黑陷的证候，泻去风火之毒，所以能救肾扶脾。）汪昂按语：泻心实际上就是补心，泻肾实际上就是救肾，邪热退去，真阴就能恢复。《兰室秘藏》（机要）中用大戟一两，大枣三枚，同煮后焙干，去掉大戟，只用大枣制成丸剂服用，名为枣变百祥丸。
杭州产的紫色大戟品质最好，北方产的白色大戟伤人。需用浆水煮制，去除骨节部分后使用。与大枣同用则不损伤脾胃。畏忌石菖蒲。与甘草相反。
Radix Euphorbiae Pekinensis (Daji) has a strong purgative effect and can unblock water-dampness pathogenic factors in the Zang-Fu organs.
It is bitter, cold, and toxic. It can purge water-dampness stagnation within the Zang-Fu organs, promote blood circulation and induce sweating, and promote urination and defecation.
It is used to treat twelve types of edema syndromes, abdominal distension with urgent pain, accumulations and masses (Zhijia), carbuncles and swellings in the neck and axilla, swelling of the lower limbs caused by wind-toxin, and to unblock menstruation and induce abortion. Accidental ingestion will damage the True Qi. (Li Shizhen said: Phlegm-fluid is a pathological product that moves up and down with the Qi, reaching everywhere. Entering the Heart leads to coma and epilepsy; entering the Lungs blocks orifices, causing cough, asthma, and coldness in the back; entering the Liver causes hypochondriac pain, dry retching, and alternating chills and fever; entering the meridians causes numbness and pain; entering the sinews and bones causes dragging dull pain; entering the skin and flesh causes scrofula and abscesses. Chen Wuzhe treated all these conditions primarily with Kongxian Dan, achieving remarkable effects. This is the fundamental treatment for phlegm. The root of phlegm is water and dampness; when combined with Qi and Fire, it condenses into phlegm. Radix Euphorbiae Pekinensis (Daji) can drain water-dampness from the Zang-Fu organs; Radix Kansui (Gansui) can circulate water-dampness through the meridians; Semen Sinapis Albae (Baijiezi) can dissipate phlegm-Qi in the interstices of the skin and fascia. Only those who skillfully utilize these herbs can achieve miraculous results.) It is also stated: Qian Yi (Qian Zhongyang) considered the Kidney as the organ of True Water, suitable only for tonification and not for purging. However, he also stated that in cases where smallpox lesions turn black and revert to the Kidney, Baixiang Gao should be used to purge them. This does not purge the Kidney itself but purges its paired Fu organ, thereby preventing the Zang organ from becoming full and stagnant. The Fu organ referred to here is the Bladder. Baixiang Gao consists solely of Radix Euphorbiae Pekinensis (Daji) because it can move water in the Bladder. Another view holds that this is not merely purging the Fu organ, but treating excess pathogenic factors in the Kidney by purging the Liver. According to the principle "excess is treated by draining its child," Radix Euphorbiae Pekinensis (Daji) turns blue-green when soaked in water, which corresponds to the colors of the Liver and Gallbladder. When smallpox toxin is abundant and fire is blazing, Kidney Water becomes increasingly depleted. Wind carrying fire depletes Spleen Earth, causing internal exhaustion of body fluids, inability to form pus, and resulting in black depression syndromes. Purging the wind-fire toxin thus saves the Kidney and supports the Spleen. Wang Ang's note: Purging the Heart actually tonifies the Heart; purging the Kidney actually saves the Kidney. Once evil heat recedes, True Yin is restored. *Jiyao* uses one liang of Radix Euphorbiae Pekinensis (Daji) and three Jujubes (Da Zao), boiled together, dried, with the Daji removed, using only the Jujube to make pills, named Zaobian Baixiang Wan.)
The purple variety produced in Hangzhou is superior; the white variety produced in the North is harmful to people. It should be decocted in rice wash water, and the woody core removed before use. Combined with Jujube (Da Zao), it does not damage the Spleen. It is incompatible with Rhizoma Acori Tatarinowii (Changpu). It is antagonistic to Radix Glycyrrhizae (Gancao).