人有腹痛口渴，左足屈而不伸，伸则痛甚，手按其痛处更不可忍，人以为肠中
生痈也，然而肠中生痈不同，有大小肠之分，屈右足者大肠生痈，屈左足者小肠生
痈也。今屈而不伸者即在左足，是痈生于小肠而非生于大肠矣。惟是大肠之痈易治，
小肠之痈难医，以大肠可泻而小肠难泻也。虽然，得其法又何不可泻哉。盖大肠可
泻其火从糟粕而出，小肠可泻其火从溲溺而泄也。方用泄毒至神汤∶
金银花（三两） 茯苓（一两） 薏仁（一两） 生甘草（三钱） 车前子（三钱）
刘寄奴（三钱） 泽泻（三钱） 肉桂（一分） 水煎服。一剂而水如注，二剂而痛顿减，
三剂而症如失，不必四剂也。
此方俱利水之药，止一味金银花消毒之味，何以建功之神如此？盖小肠之毒必
须内消，而内消之药，舍金银花实无他药可代，以他药消毒皆能损伤正气，而小肠
断不可损伤，故必须以金银花为君。但金银花不能入小肠之中，今同茯苓、薏仁、
泽泻、车前子之类引入小肠，又加肉桂一分，得其气味引入膀胱，从溲溺而化。又
恐火毒太盛，诸药不能迅逐，更加刘寄奴之速祛，甘草之缓调，刚柔迟速并行，既
无留滞之虞，而复无峻烈之害，自然火毒殆尽膀胱小肠而出也。
人有腹痛呼号不已，其痛却在左腹，按之痛不可忍，不许人按，医以为食积在
大肠也，谁知是小肠之生痈耳。凡肠痈必屈其足，而今不屈足，似非肠痈之病。
然肠痈生于肠内者必屈其足。在大肠者屈右足而不伸，在小肠屈左足而不伸也。
若痈生于肠外者，皆不屈足。痛在左则小肠生痈，痛在右则大肠生痈也。至食积燥
屎之痛，时而痛，时而不痛。故痛在左，明是小肠之外生痈也。大小肠生痈于肠内
尚可破溃，而大小肠生痈于肠外断不可使之破溃者，以肠外无可出之路，皆必死之
症也，而小肠更甚，必须急早治之。方用内化丹∶
金银花（四两） 当归（二两） 车前子（五钱） 生甘草（三钱） 茯苓（一两） 薏仁（一两）
水煎服。
一剂而痛大减，二剂而痛又减，三剂而痛全止，四剂全愈。
此方即前方之变方也。但前方以利水之中而行其败毒之法，此方于利水之中补
血以败毒之法也。盖痈破利水则毒随水出，易于祛除；痈未破，不补血以利水，则
水泄而血虚，难于消化，同中之异，不可不知也。然此方亦须急早治之则有益，否
则痈虽愈而瘀血流于肠外，必有终身腹痛之病也。
人有腹痛骤甚，小便流血，左足不能伸，人以为小肠生痈也，谁知是小肠之火
太盛耳。夫小肠生痈，必屈左足，今左足不伸，明是生痈之证，而予独谓是火盛者
何故？不知生痈必有其征，未有一旦骤生而即流血者也。痈日久而脓生，脓欲尽而
血出，岂有不溃不烂而先出血者。然左足之屈则又何也？盖小肠与大肠不同，小肠
细而大肠宽，宽者可以容邪，而细者难以容邪，此必然之理。小肠受火煎熬，则肠
中逼迫，肠不能舒，而左足应之，故暂屈而不伸耳。但不可因足之不伸即信是痈，
而妄用解毒之药。然从何处辨之？因其初病之时，辨其小便之有血无血耳。初起痛
而足屈，若小便无血，乃是生痈；初起痛而足屈，小便有血，乃是火痛，断不可瘥
也。治之法泻其火邪，不必化毒而痛止足伸矣。方用小柴胡汤加味治之。
柴胡（一钱） 黄芩（三钱） 甘草（一钱） 茯苓（五钱） 人参（二钱） 半夏（一钱）
水煎服。一剂而足伸，二剂而血止，肠亦不痛矣。
小柴胡汤非治小肠之药也，何以用之而效验之捷如此。因小肠之火盛者，起于
肝胆之郁也，木郁则火生，不敢犯心而犯小肠耳。夫火性炎上，今不上炎，反致下
炽，拂其火性矣，此小肠所以受之而作疼痛也。至于流血于小便中者，又是何故？
盖是小肠之血为火所逼，惟恐为火之烁干，故越出于小肠之外，直走膀胱，反使火
道不行而流血也。小柴胡汤既舒其肝胆之气，则火气上炎，其生既顺而不逆。又
得茯苓以清消其水气，水流而血自归经，此方之所以奇耳。
[Background Information]
Book: Bian Zheng Lu (Record of Syndrome Differentiation)
Author: Chen Shiduo
Dynasty: Qing
Chapter: Xiao Chang Yong Men (Section on Small Intestine Abscess, Three Cases)
Category: Comprehensive
[English Translation]
A patient presents with abdominal pain and thirst, with the left leg flexed and unable to extend. Extension exacerbates the pain, and palpation of the painful area is intolerable. Laypeople might assume this is an abscess (Zhongyi term for internal suppurative disease) in the intestines. However, intestinal abscesses differ between the large intestine and the small intestine. Flexion of the right leg indicates a large intestine abscess, while flexion of the left leg indicates a small intestine abscess. Since the patient’s left leg is flexed and cannot extend, the abscess is located in the small intestine, not the large intestine. Generally, large intestine abscesses are easier to treat because their pathogenic factors can be purged via feces, whereas small intestine abscesses are difficult to treat because they are hard to purge via defecation. Nevertheless, if the correct method is employed, purgation is possible. The fire-heat in the large intestine exits through feces, while the fire-heat in the small intestine exits through urine. The prescription used is Xi Du Zhi Shen Tang (Toxin-Draining Supreme Divine Decoction): Jin Yin Hua (Lonicerae Japonicae Flos, 3 liang), Fu Ling (Poria, 1 liang), Yi Ren (Coicis Semen, 1 liang), Sheng Gan Cao (Glycyrrhizae Radix et Rhizoma Preparata, 3 qian), Che Qian Zi (Plantaginis Semen, 3 qian), Liu Ji Nu (Artemisiae Anethifoliae Herba, 3 qian), Ze Xie (Alismatis Rhizoma, 3 qian), Rou Gui (Cinnamomi Cortex, 1 fen). Decoct in water and take orally. After one dose, urination becomes profuse like a stream; after two doses, pain decreases significantly; after three doses, symptoms disappear completely, without needing a fourth dose.
This formula consists mainly of diuretic herbs, with only one herb, Jin Yin Hua (Lonicerae Japonicae Flos), possessing detoxifying properties. Why does it achieve such miraculous results? The toxin in the small intestine must be resolved internally. Among internal-resolving herbs, Jin Yin Hua (Lonicerae Japonicae Flos) has no substitute, as other detoxifying herbs damage healthy Qi (Vital Energy), which must not happen in the small intestine. Thus, Jin Yin Hua (Lonicerae Japonicae Flos) serves as the sovereign herb. However, Jin Yin Hua (Lonicerae Japonicae Flos) alone cannot enter the small intestine. It is guided into the small intestine by Fu Ling (Poria), Yi Ren (Coicis Semen), Ze Xie (Alismatis Rhizoma), and Che Qian Zi (Plantaginis Semen). Additionally, a small amount of Rou Gui (Cinnamomi Cortex) guides the qi and flavor into the bladder, allowing resolution through urination. To prevent excessive fire-toxin from resisting rapid expulsion, Liu Ji Nu (Artemisiae Anethifoliae Herba) is added for swift removal of stasis, and Gan Cao (Glycyrrhizae Radix et Rhizoma Preparata) is added for gentle regulation. This combination of firm and soft, slow and fast actions prevents stagnation without causing harsh side effects, ensuring that fire-toxin is entirely expelled via the bladder and urine.
Another patient suffers from incessant crying due to abdominal pain localized in the left abdomen. Palpation is intolerable, and the patient refuses touch. Physicians may diagnose food retention in the large intestine, but it is actually a small intestine abscess. Typically, intestinal abscesses cause the patient to flex their legs. The current lack of leg flexion might suggest it is not an intestinal abscess. However, abscesses *inside* the intestine cause leg flexion: right leg flexion indicates large intestine involvement, and left leg flexion indicates small intestine involvement. If the abscess is *outside* the intestine, leg flexion does not occur. Pain on the left indicates a small intestine abscess; pain on the right indicates a large intestine abscess. In contrast, pain from food retention or dry stool is intermittent. Therefore, persistent pain on the left clearly indicates an external small intestine abscess. Abscesses inside the large or small intestine can be allowed to rupture and drain, but those outside cannot, as there is no exit pathway, leading to certain death. This is especially critical for the small intestine, requiring urgent treatment. The prescription used is Nei Hua Dan (Internal-Dissolving Pill/Decoction): Jin Yin Hua (Lonicerae Japonicae Flos, 4 liang), Dang Gui (Angelicae Sinensis Radix, 2 liang), Che Qian Zi (Plantaginis Semen, 5 qian), Sheng Gan Cao (Glycyrrhizae Radix et Rhizoma Preparata, 3 qian), Fu Ling (Poria, 1 liang), Yi Ren (Coicis Semen, 1 liang). Decoct in water and take orally.
After one dose, pain decreases significantly; after two doses, it decreases further; after three doses, pain ceases completely; after four doses, full recovery occurs.
This formula is a variation of the previous one (Xi Du Zhi Shen Tang). The previous formula promotes detoxification within diuresis, whereas this formula promotes detoxification within blood-nourishing diuresis. When an abscess has ruptured, diuresis helps expel toxins easily. When an abscess has not ruptured, diuresis without blood nourishment leads to fluid loss and blood deficiency, making toxin resolution difficult. These nuances must be understood. Urgent treatment is still required; otherwise, even if the abscess heals, blood stasis flowing outside the intestine will cause lifelong abdominal pain.
A third patient experiences sudden severe abdominal pain, hematuria (blood in urine), and inability to extend the left leg. People suspect a small intestine abscess, but it is actually excessive fire-heat in the small intestine. A small intestine abscess typically causes left leg flexion. Since the leg is not extending, it appears to be an abscess. Why do I attribute it to excess fire? Abscesses have specific signs; they do not appear suddenly with bleeding. Abscesses produce pus over time, and blood appears only when pus is nearly exhausted. How could there be bleeding before ulceration? Then why is the left leg flexed? The small intestine is narrow, while the large intestine is wide. The wide intestine can accommodate pathogens, but the narrow one cannot. This is a fundamental principle. When the small intestine is scorched by fire, internal pressure increases, preventing the intestine from relaxing, which reflexively causes the left leg to flex temporarily. One should not assume it is an abscess solely based on leg position and blindly use detoxifying herbs. How to differentiate? Observe the presence or absence of blood in the urine at onset. If pain and leg flexion occur without blood in the urine, it is an abscess. If pain and leg flexion occur with blood in the urine, it is fire-pain, which will not heal spontaneously. The treatment is to purge the fire-pathogen; detoxification is unnecessary, and pain will cease while the leg extends. The prescription is Xiao Chai Hu Tang (Minor Bupleurum Decoction) with modifications: Chai Hu (Bupleuri Radix, 1 qian), Huang Qin (Scutellariae Radix, 3 qian), Gan Cao (Glycyrrhizae Radix et Rhizoma Preparata, 1 qian), Fu Ling (Poria, 5 qian), Ren Shen (Ginseng Radix, 2 qian), Ban Xia (Pinelliae Rhizoma Preparatum, 1 qian). Decoct in water and take orally. After one dose, the leg extends; after two doses, bleeding stops, and intestinal pain ceases.
Xiao Chai Hu Tang (Minor Bupleurum Decoction) is not typically a direct treatment for the small intestine. Why is it so effective here? Excessive fire in the small intestine originates from liver-gallbladder Qi stagnation. Wood stagnation generates fire, which attacks the small intestine rather than the heart. Fire naturally flares upward; here, it fails to rise and instead blazes downward, violating its nature, causing small intestine pain. As for blood in the urine, the fire forces blood out of the small intestine vessels to avoid being dried up by the heat. The blood escapes the small intestine, flows directly into the bladder, obstructs the fire pathway, and results in bleeding. Xiao Chai Hu Tang (Minor Bupleurum Decoction) soothes liver-gallbladder Qi, allowing fire to rise smoothly and naturally. Combined with Fu Ling (Poria) to clear dampness/water, the flow of water allows blood to return to its vessels. This synergy explains the miracle of this formula.