二十、如果患者频繁想要漱口但不想吞咽，大便颜色发黑且排出顺畅的，这是体内有瘀血的表现，应当使用犀角地黄汤进行治疗。
病邪位于血分，患者不想喝水；但因热邪耗伤津液导致口干，又渴望通过水来缓解，所以只是想要含漱口水，而不愿吞咽下去。瘀血溢出到肠道之间，血液淤积久了颜色就会变黑；由于血液本性柔润，所以大便虽然发黑但排出不难。犀角味道咸，能进入下焦血分以清除热邪；地黄能消除体内的积聚并滋补阴液；白芍能去除恶血、生成新血；丹皮能泻除血中潜伏的火邪。这样蓄积的血液自然能够向下排泄，因此使用这种轻缓的方剂来调理它。
犀角地黄汤方（遵循甘、咸、微苦的法度）
干地黄（一两） 生白芍（三钱） 牡丹皮（三钱） 犀角（三钱）
用水五杯，煮取两杯药汁，分两次服用，药渣再煮一杯药汁服用。
20. If the patient frequently desires to rinse their mouth but does not wish to swallow, and the stool is black yet easy to pass, this indicates the presence of blood stasis (Blood Stasis). It should be treated with Xijiao Dihuang Tang (Rhinoceros Horn and Rehmannia Decoction).
When the pathogen resides in the Blood aspect, there is no desire for drinking water. However, due to heat pathogens consuming body fluids causing dryness of the mouth, there is a desire to seek relief from water; thus, one only wishes to rinse the mouth without swallowing. When blood stasis overflows into the intestines, the color of the blood turns black after long-term stagnation. Since blood nature is soft and moist, the stool becomes black but passes easily. Rhinoceros horn (Xijiao) has a salty taste and enters the Lower Jiao Blood aspect to clear heat; Rehmannia root (Dihuang) eliminates accumulations and nourishes Yin; White Peony root (Baishao) removes bad blood and generates new blood; Moutan bark (Danpi) drains latent fire within the blood. Thus, the accumulated blood naturally flows downward, so this mild formula is used to regulate it.
Formula of Xijiao Dihuang Tang (Following the method of Sweet, Salty, and Slightly Bitter)
Prepared Rehmannia Root (Gan Dihuang) [Rehmanniae Radix Preparata] (1 liang)
Raw White Peony Root (Sheng Baishao) [Paeoniae Radix Alba] (3 qian)
Moutan Bark (Danpi) [Moutan Cortex] (3 qian)
Rhinoceros Horn (Xijiao) [Rhinocerotis Cornu] (3 qian)
Boil five cups of water until two cups remain. Divide into two doses for administration. Boil the dregs again to obtain one cup for administration.