大小便蓄血，便血，不论伤寒时疫，盖因失下，邪热久羁，无由以泄，血为热搏
，留于经络，败为紫血，溢于肠胃，腐为黑血，便色如漆，大便反易者，虽结粪得瘀而润下
，结粪虽行，真元已败，多至危殆。其有喜忘如狂者，此胃热波及于血分，血乃心之属，血
中留火延蔓心家，宜其有是证矣。仍从胃治。
发黄一证，胃实失下，表里壅闭，郁而为黄，热更不泄，搏血为瘀。凡热经气不郁，不致发
黄，热不干血分，不致蓄血，同受其邪，故发黄而兼蓄血，非蓄血而致发黄也。但蓄血一行
，热随血泄，黄因随减。尝见发黄者，原无瘀
血，有瘀血者，原不发黄。所以发黄，当咎在经瘀热，若专治瘀血误也。胃移热于下焦气分
，小便不利，热结膀胱也。移热于下焦血分，膀胱蓄血也。小腹硬满，疑其小便不利，今小
便自利者，责之蓄血也。小便不利亦有蓄血者，非小便自利便为蓄血也。胃实失下，至夜发热者，热
留血分，更加失下，必致瘀血。初则昼
夜发热，日晡益甚，既投承气，昼日热减，至夜独热者，瘀血未行也，宜桃仁承气汤。服汤
后
热除为愈，或热时前后缩短，再服再短，蓄血尽而热亦尽。大势已去，亡血过多，余焰尚存
者，宜犀角地黄汤调之。至夜发热，亦有瘅疟，有热入血室，皆非蓄血，并未可下，宜审。
桃仁承气汤
大黄 芒硝 桃仁 当归 芍药 丹皮
照常煎服。
犀角地黄汤
地黄（一两） 白芍（三钱） 丹皮（二钱） 犀角（二钱，研碎）
上先将地黄温水润透，铜刀切作片，石臼内捣烂，再加水如糊，绞汁听用，其滓入药同煎
，药成去滓，入前汁合服。
按∶伤寒太阳病不解，从经传腑，热结膀胱，其人如狂，血自下者愈。血结不行者，宜抵当
汤。今温疫起无表证，而惟胃实，故肠胃蓄血多，膀胱蓄血少。然抵当汤行瘀逐蓄之最者，
无
分前后二便，并可取用。然蓄血结甚者，在桃仁力所不及，宜抵当汤。盖非大毒猛厉之剂，
不足以抵当，故名之。然抵当证，所遇亦少，此以备万一之用。
抵当汤
大黄（五钱） 虻虫（二十枚，炙干，研末） 桃仁（五钱，研加酒） 水蛭（炙干为末，五分）
照常煎服。
大小便蓄血，以及便血，无论是伤寒还是时疫，大概是因为失于攻下，邪热长期滞留，没有途径宣泄，血液被热邪搏结，停留在经络中，腐败成为紫黑色的血，溢出到肠胃里，腐烂变成黑血，大便颜色像漆一样黑。虽然大便反而容易排出，这是因为燥结的粪便得到瘀血的滋润而下行，但即使燥结的粪便排出了，人体的真元之气已经败坏，大多会发展到危重地步。
那些出现健忘、神情恍惚如发狂症状的人，这是胃中的热邪波及到血分。血属于心所主，血中留存的火邪蔓延侵扰心神，所以会出现这些症状。治疗仍应从胃（清热）入手。
发黄这一证候，是由于胃中实热失于攻下，表里气机壅闭，郁蒸而发黄；如果热邪不能宣泄，搏结血液形成瘀血。凡是热邪在气分运行而不郁滞，就不会导致发黄；热邪不干扰血分，就不会导致蓄血。因为两者同受邪气影响，所以可能出现发黄兼有蓄血的情况，但这并非蓄血导致了发黄。只要蓄血得以疏通，热邪随血液外泄，黄疸就会随之减轻。我曾经见到发黄的患者，原本并没有瘀血；而有瘀血的患者，原本并不发黄。所以导致发黄的原因，应当归咎于经络中瘀积的热邪，如果专门治疗瘀血就是错误的。
胃将热邪移注到下焦气分，导致小便不利，这是热结膀胱。将热邪移注到下焦血分，则是膀胱蓄血。小腹部硬满，让人怀疑是小便不利引起的，但如果现在小便自利通畅的，就要责之于蓄血。小便不利也有属于蓄血情况的，并不是只有小便自利才算是蓄血。
胃中实热失于攻下，到了夜间发热，这是热邪留在血分；如果再失于攻下，必然导致瘀血。起初是昼夜都发热，傍晚时分加重；既然投用了承气汤后，白天的热势减退，但到了夜间仍然单独发热的，说明瘀血尚未消散，适宜使用桃仁承气汤。服用汤药后，热势消除即为痊愈；或者发热的时间段前后缩短，再次服药后时间更短，直到蓄血尽除，热邪也就完全清除。如果大势已去，亡血过多，但残余的热焰尚存，适宜用犀角地黄汤来调理。
至于夜间发热，也有可能是瘅疟，或者是热入血室，这些都不是蓄血，都不可使用攻下法，应当仔细辨别。
桃仁承气汤
大黄 芒硝 桃仁 当归 芍药 丹皮
按照常规方法煎煮服用。
犀角地黄汤
地黄（一两） 白芍（三钱） 丹皮（二钱） 犀角（二钱，研碎）
先将地黄用温水润透，用铜刀切成片，放入石臼中捣烂，再加水调成糊状，绞取汁液备用；剩下的药渣加入药物中同煎。药煎好后去掉药渣，将之前备好的汁液混合服用。
按语：伤寒太阳病如果不解除，病邪从经传入腑，热结于膀胱，病人出现如狂的症状，如果瘀血能自行排出则病愈。如果血结不行，适宜使用抵当汤。现在的温疫病起病就没有表证，只有胃家实，所以肠胃蓄血的情况多，膀胱蓄血的情况少。然而，抵当汤是行瘀逐蓄作用最强的方剂，无论前阴或后阴的蓄血，都可以选用。但是蓄血结聚严重的，桃仁承气汤的力量达不到，适宜使用抵当汤。大概如果不是大毒猛烈的药剂，不足以抵挡这种严重的瘀血，所以名叫抵当汤。然而抵当汤的适应证遇到的也较少，这里列出是为了防备万一之用。
Blood stasis in the large and small intestines, as well as hematochezia (blood in stool), whether due to Shanghan (Cold Damage) or Shi Yi (Epidemic Febrile Disease), is generally caused by failure to use purgatives. The pathogenic heat lingers for a long time without an outlet to vent. Blood is constrained by the heat, remains in the collaterals, decomposes into purple blood, overflows into the stomach and intestines, and rots into black blood. The stool color is like lacquer. Although defecation may seem easier because the dry feces are moistened by the blood stasis and descend, even if the dry feces pass, the vital essence (Zhen Yuan) has already been depleted, often leading to a critical condition.
Those who exhibit forgetfulness and a manic-like state have this condition because stomach heat affects the blood level. Since blood belongs to the Heart, fire retained in the blood spreads to disturb the Heart spirit, hence these symptoms. Treatment should still focus on the Stomach (clearing heat).
The syndrome of jaundice arises when excess heat in the Stomach fails to be purged, causing obstruction in both the interior and exterior, leading to stagnation and yellowing. If heat cannot vent and constrains blood to form stasis, it becomes complicated. Generally, if heat circulates in the Qi level without stagnation, jaundice does not occur; if heat does not interfere with the Blood level, blood stasis does not accumulate. Since both are affected by the same pathogen, jaundice may coexist with blood stasis, but this is not blood stasis causing jaundice. Once blood stasis is resolved, heat vents with the blood, and jaundice diminishes accordingly. I have observed patients with jaundice who originally had no blood stasis, and patients with blood stasis who originally did not have jaundice. Therefore, the cause of jaundice lies in stagnant heat in the meridians; treating only blood stasis would be a mistake.
When Stomach heat transfers to the Qi level of the Lower Jiao, resulting in difficult urination, this is heat binding the Bladder. When heat transfers to the Blood level of the Lower Jiao, it results in blood stasis in the Bladder. A hard and full sensation in the lower abdomen might suggest difficult urination, but if urination is now free and unobstructed, the cause must be attributed to blood stasis. Note that difficult urination can also be associated with blood stasis; it is not the case that only free urination indicates blood stasis.
If Stomach excess heat is not purged and fever occurs at night, this is heat remaining in the Blood level. Further failure to purge will inevitably lead to blood stasis. Initially, there is fever day and night, worsening in the late afternoon. After administering Chengqi Tang, if daytime fever subsides but night fever persists alone, it indicates that blood stasis has not yet moved. Tao Ren Chengqi Tang is indicated. After taking the decoction, if the fever disappears, the patient recovers. If the duration of fever shortens each time the medicine is taken, until the blood stasis is exhausted and the fever completely resolves. If the major pathogenic factors have passed but excessive blood loss has occurred, leaving residual heat, Xijiao Dihuang Tang is suitable to regulate the condition.
Nighttime fever can also be caused by Dan Nue (Malaria with high fever) or Re Ru Xue Shi (Heat entering the Blood Chamber). These are not blood stasis and should not be treated with purgatives; careful differentiation is required.
Tao Ren Chengqi Tang
Dahuang (Rhei Radix et Rhizoma)
Mangxiao (Natrii Sulfas)
Taoren (Persicae Semen)
Danggui (Angelicae Sinensis Radix)
Shaoyao (Paeoniae Radix Alba)
Danpi (Moutan Cortex)
Prepare and administer according to standard decoction methods.
Xijiao Dihuang Tang
Dihuang (Rehmanniae Radix Praeparata) - 1 liang
Baishao (Paeoniae Radix Alba) - 3 qian
Danpi (Moutan Cortex) - 2 qian
Xijiao (Rhino Ceratis Cornu) - 2 qian, crushed
First, moisten Dihuang with warm water until soft, slice it with a copper knife, and pound it in a stone mortar until pulpy. Add water to make a paste, squeeze out the juice, and set aside. Put the dregs back into the medicinal pot to decoct with other herbs. After decoction, remove the dregs, and mix with the previously prepared juice before administration.
Commentary: In Shanghan, if the Taiyang disease does not resolve, the pathogen transmits from the meridians to the fu organs, causing heat to bind the Bladder. The patient exhibits a manic-like state. If blood stasis discharges spontaneously, the disease heals. If blood stasis does not move, Didang Tang is indicated. However, Wenyi (Warm Epidemic) diseases begin without exterior syndromes and present primarily with Stomach excess. Therefore, blood stasis in the stomach and intestines is common, while blood stasis in the Bladder is rare. Nevertheless, Didang Tang is the most potent formula for moving stasis and expelling accumulation, applicable to both anterior (urinary) and posterior (intestinal) blood stasis. For severe cases where Tao Ren Chengqi Tang is insufficient, Didang Tang is appropriate. It is named "Didang" because only such a potent and fierce agent can withstand (di dang) such severe stasis. However, indications for Didang Tang are rare; this is included for emergency reference.
Didang Tang
Dahuang (Rhei Radix et Rhizoma) - 5 qian
Mengchong (Blaberus spp.) - 20 pieces, roasted dry, powdered
Taoren (Persicae Semen) - 5 qian, ground with wine
Shizhi (Hirudo) - Roasted dry, powdered, 5 fen
Prepare and administer according to standard decoction methods.