伤寒自利。何以明之。自利者。有不经攻下。自然溏泄者。谓之自利也。伤寒自利多
种。须知冷热虚实。消息投汤。无致失瘥。杂病自利。多责为寒。伤寒下利。多由协热。
其与杂病有以异也。表邪传里。里虚协热则利。不应下而便攻之。内虚协热遂利。
是皆协热。已又合病。皆作自利。太阳与阳明合病。必自下利。葛根汤主之。太阳与
少阳合病。必自下利。黄芩汤主之。阳明与少阳合病。必自下利。大承气汤主之。三
者皆合病下利。一者发表。一者攻里。一者和解。所以不同者。盖六经以太阳阳明
为表。少阳太阴为在半表半里。少阴厥阴为在里。太阳阳明合病。为在表者也。虽
曰下利。必发散经中邪气而后已。故与葛根汤以汗之。太阳与少阳合病。为在半
表半里者也。虽曰下利。必和解表里之邪而后已。故与黄芩汤以散之。阳明少阴
合病。为少阳邪气入腑者也。虽曰下利。必逐去胃中之实而后已。故与承气汤以
下之。是三者所以有异也。下利家何以明其寒热耶。且自利不渴属太阴。以其脏
寒故也。下利欲饮水者。以有热也。故大便溏小便自可者。此为有热自利。小便色
白者。少阴病形悉具。此为有寒。恶寒脉微。自利清谷。此为有寒。发热后重。泄色黄
赤。此为有热。皆可理其寒热也。凡腹中痛。转气下趋少腹者。此欲自利也。自利家
身凉脉小为顺。身热脉大为逆。少阴病脉紧下利。脉暴微。手足反温。脉紧反去者。
此为欲解。下利脉大者为未止。脉微弱数者。为欲自止。虽发热不死。是知下利脉
大为逆。而脉小为顺也。自利宜若可温。理中白通诸四逆辈。皆温脏止利之剂。又
有肠胃有积结。与下焦客邪。皆温剂不能止之。必也或攻泄之。或分利之而后已。
经曰。理中者理中焦。此利在下焦。宜赤石脂禹余粮汤。复不止。当利其小便。是湿
在下焦。渗泄而聚利者也。少阴病自利清水。色纯青。心下必痛。口干燥。与下利三
部皆平。按之心下硬。或脉沉而滑。或不欲食而谵语。或瘥后至年月日复发。此数
者。皆肠胃有积结。而须攻泄者也。内经有曰。大热内结。注泄不止。热宜寒疗。结伏
须除。以寒下之。结散利止。大寒凝内。久利泄溏。愈而复发。绵历岁年。以热下之。寒
去利止。谓之通因通用。下利虽有表证。又不可发汗。以下利为邪气内攻。走津液
而胃虚也。故经曰。下利不可攻其表。汗出必胀满者是矣。大抵下利脱气至急。五
夺之中。此为甚者。其或邪盛正虚。邪壅正气下脱。多下利而死。何以言之。经曰。下
利日十余行。脉反实者死。发热下利至甚。厥不止者死。直视谵语下利者死。下利
手足厥冷无脉者。灸之不温。脉不还死。少阴病自利。复烦躁不得卧寐者死。此数
者。皆邪壅正气下脱而死者也。金匮要略曰。六腑气绝于外者。手足寒。五脏气绝
于内者。利下不禁。呜呼。疾成而后药。虽神医不可为已。气既脱矣。孰能治之。
伤寒病中的自利（未经攻下而自然发生的腹泻），该如何阐明呢？所谓自利，是指没有经过泻下治疗，却自然出现大便溏薄泄泻的情况，这就叫做自利。伤寒病的自利有多种类型，必须分辨其寒、热、虚、实的不同，仔细斟酌后投予相应的汤药，以免延误病情导致无法痊愈。杂病中的自利，多责之于寒邪；而伤寒病中的下利，多由“协热”（表邪入里化热或表里同病之热）所致。这与杂病是有区别的。
如果表邪传入体内，因里气虚弱且伴有热邪而导致下利；或者本不应使用攻下法却误用攻下，导致内里虚弱并伴有热邪而下利；这些都属于“协热利”。此外，还有合病情况，也会表现为自利。例如：太阳经与阳明经合病，必然出现自下利，应用葛根汤主治；太阳经与少阳经合病，必然出现自下利，应用黄芩汤主治；阳明经与少阳经合病，必然出现自下利，应用大承气汤主治。这三种合病导致的下利，治疗方法各不相同：一种是发汗解表，一种是攻逐里实，一种是和解表里。之所以不同，是因为六经中，太阳和阳明属于表证，少阳和太阴属于半表半里证，少阴和厥阴属于里证。太阳与阳明合病，病位在表，虽然出现下利，但必须发散经络中的邪气才能痊愈，所以给予葛根汤通过发汗来治疗。太阳与少阳合病，病位在半表半里，虽然出现下利，但必须和解表里之邪才能痊愈，所以给予黄芩汤来疏散邪气。阳明与少阳合病（注：原文此处疑为笔误，结合上下文及《伤寒论》常理，此处指阳明腑实或少阳邪气入腑，通常对应大承气汤证），是少阳邪气传入腑脏的表现，虽然出现下利，但必须清除胃中的实邪才能痊愈，所以给予承气汤通过泻下来治疗。这就是三者不同的原因。
对于下利的患者，如何辨别其寒热性质呢？一般来说，自利且不口渴的，属于太阴病，因为内脏有寒的缘故。如果下利且想喝水的，是因为体内有热。所以，大便溏薄但小便正常的，这是有热导致的自利；如果小便颜色清白，则是少阴病的典型表现，这属于有寒。如果恶寒且脉象微弱，下利排出未消化的食物（清谷），这也是有寒。如果发热且有肛门重坠感（后重），排泄物颜色黄赤，这是有热。这些都可以通过症状来辨析寒热。
凡是腹中疼痛，感觉气体向下移动至小腹的，这是即将发生自利的征兆。自利患者如果身体凉爽、脉象细小，属于顺证；如果身体发热、脉象洪大，属于逆证。少阴病出现脉紧且下利，如果脉搏突然变得微弱，但手足反而转温，脉紧的感觉消失，这是病情将要解除的迹象。如果下利患者脉象洪大，说明病势未止；如果脉象微弱而数，说明下利将要自行停止，即使伴有发热也不会死亡。由此可知，下利见脉大为逆证，见脉小为顺证。
自利通常适宜用温法治疗，理中汤、白通汤以及各类四逆汤等，都是温补脏腑、止住下利的方剂。但是，如果肠胃中有积滞结聚，或者下焦有客邪停留，单纯用温药是不能止住的，必须采用攻下泄浊或分利小便的方法才能痊愈。经典记载：“理中汤是调理中焦的”，此处的下利位于下焦，适宜用赤石脂禹余粮汤。如果服用后仍不止泻，应当通利小便，这是因为湿气在下焦，通过渗湿泄浊来聚集止利。如果是少阴病，自利排出纯青色的清水，心下部必定疼痛，口干燥，这属于下利三部（上、中、下三焦）皆平的情况；如果按压心下部感觉坚硬，或者脉象沉而滑，或者不想吃东西且说胡话（谵语），或者病愈后在特定的年月日复发，这几种情况，都是因为肠胃中有积滞结聚，需要采用攻下泄浊的方法。《内经》说：“大热内结，导致泄泻不止，热邪宜用寒凉疗法，结伏之邪必须去除，用寒下药攻之，结散则利止。”反之，“大寒凝滞于内，导致久利泄泻溏薄，病愈后复发，绵延多年，用温热药攻之，寒去则利止。”这叫做“通因通用”（即用通利的方法治疗具有通利症状的病证）。
下利虽然有表证，也不可以发汗，因为下利意味着邪气向内攻伐，耗伤津液且胃气虚弱。所以经典说：“下利不可攻其表，若发汗导致出汗，必然会出现腹部胀满。”大抵来说，下利导致元气脱失是非常紧急的情况，在“五夺”（五种极度虚损的状态）之中，这属于严重的情况。如果邪气盛而正气虚，邪气壅滞导致正气下脱，往往会导致下利而死。为什么这样说呢？经典说：“下利每天十几次，脉象反而实大的，主死；发热下利非常严重，四肢厥冷不能回温的，主死；眼睛直视、说胡话且下利的，主死；下利且手足厥冷无脉的，即使艾灸也不能回暖，脉象不恢复的，主死；少阴病自利，又烦躁不得卧睡的，主死。”这几种情况，都是因为邪气壅滞、正气下脱而死亡的缘故。《金匮要略》说：“六腑之气在外衰竭，表现为手足寒冷；五脏之气在内衰竭，表现为下利不禁。”唉！疾病形成后才用药，即使是神医也无法救治了。既然元气已经脱失，谁能治愈它呢？
**Spontaneous Diarrhea in Cold Damage**
How should spontaneous diarrhea (Zili, diarrhea occurring naturally without prior purgative treatment) in Cold Damage be elucidated? Spontaneous diarrhea refers to the condition where loose stools and diarrhea occur naturally without having undergone purgative therapy. There are various types of spontaneous diarrhea in Cold Damage; one must discern whether it is due to cold, heat, deficiency, or excess, carefully select the appropriate decoction, and avoid failing to achieve recovery. In miscellaneous diseases, spontaneous diarrhea is often attributed to cold; however, in Cold Damage, diarrhea is mostly caused by "cooperating heat" (Xiere, heat associated with pathogenic factors entering the interior or simultaneous exterior-interior involvement). This differs from miscellaneous diseases.
If exterior pathogens transmit to the interior, causing diarrhea due to interior deficiency combined with heat; or if purgatives are incorrectly used when not indicated, leading to interior deficiency and heat-induced diarrhea; these all fall under "cooperating heat diarrhea." Furthermore, concurrent diseases (Hebing) also manifest as spontaneous diarrhea. For instance:
1. Concurrent disease of the Taiyang and Yangming channels inevitably results in spontaneous diarrhea, treated primarily with Gegen Tang (Pueraria Decoction).
2. Concurrent disease of the Taiyang and Shaoyang channels inevitably results in spontaneous diarrhea, treated primarily with Huangqin Tang (Scutellaria Decoction).
3. Concurrent disease of the Yangming and Shaoyang channels inevitably results in spontaneous diarrhea, treated primarily with Dachengqi Tang (Major Order the Qi Decoction).
These three types of diarrhea arising from concurrent diseases have different treatments: one involves releasing the exterior through sweating, one involves attacking the interior excess, and one involves harmonizing the exterior and interior. The reason for this difference lies in the Six Channels theory: Taiyang and Yangming are considered exterior, Shaoyang and Taiyin are semi-exterior/semi-interior, and Shaoyin and Jueyin are interior.
- Taiyang-Yangming concurrent disease is located in the exterior. Although diarrhea occurs, the pathogenic qi in the meridians must be dispersed to resolve the condition. Therefore, Gegen Tang is administered to induce sweating.
- Taiyang-Shaoyang concurrent disease is located in the semi-exterior/semi-interior. Although diarrhea occurs, the pathogenic factors in both the exterior and interior must be harmonized to resolve the condition. Therefore, Huangqin Tang is administered to disperse the pathogen.
- Yangming-Shaoyang concurrent disease (Note: Text implies Shaoyang pathogen entering the Fu organs/Yangming Fu excess) represents the Shaoyang pathogen entering the Fu organs. Although diarrhea occurs, the solid accumulation in the stomach/intestines must be expelled to resolve the condition. Therefore, Chengqi Tang is administered to purge downward. These are the reasons for their differences.
How can one distinguish between cold and heat in patients with diarrhea? Generally, spontaneous diarrhea accompanied by no thirst indicates a Taiyin pattern, due to cold in the zang organs. If diarrhea is accompanied by a desire to drink water, it indicates the presence of heat. Thus, loose stools with normal urination indicate heat-induced spontaneous diarrhea. If the urine is clear and white, it presents the full picture of a Shaoyin disease, indicating cold. Aversion to cold with a faint pulse, and diarrhea passing undigested food (Qinggu), also indicate cold. Fever accompanied by tenesmus (Houzhong, a feeling of incomplete defecation) and yellow-red excrement indicate heat. These symptoms allow for the differentiation of cold and heat.
Abdominal pain with a sensation of gas moving downward toward the lower abdomen indicates impending spontaneous diarrhea. In patients with diarrhea, a cool body and small pulse are favorable signs (Shun); a hot body and large pulse are unfavorable signs (Ni). In Shaoyin disease, if the pulse is tight and there is diarrhea, but the pulse suddenly becomes faint while the hands and feet turn warm, and the tightness of the pulse disappears, this indicates the disease is about to resolve. If the pulse is large during diarrhea, the condition has not yet stopped. If the pulse is faint and rapid, the diarrhea is likely to stop spontaneously; even if fever is present, death will not occur. Thus, a large pulse in diarrhea is an unfavorable sign, while a small pulse is favorable.
Spontaneous diarrhea is generally suitable for warming treatments. Lizhong Tang (Regulate the Middle Decoction), Baitong Tang (White Tongue Decoction), and various Si Ni Tang (Frigid Extremities Decoctions) are agents that warm the viscera and stop diarrhea. However, if there are accumulations and knots in the intestines and stomach, or external pathogens in the lower jiao, warming agents alone cannot stop the diarrhea. One must either purge and drain or separate and benefit urination to resolve the condition. The classics state: "Lizhong Tang regulates the middle jiao." Since this diarrhea is in the lower jiao, Chishizhi Yuyuli Tang (Red Stone Lipstick and Hematite Decoction) is appropriate. If it still does not stop, one should promote urination, as dampness is in the lower jiao, accumulating and causing diarrhea; promoting diuresis resolves it.
In Shaoyin disease, if spontaneous diarrhea produces pure green water, there must be pain in the epigastrium and dryness in the mouth. This falls under the category where the three parts (upper, middle, lower jiao) are relatively balanced. If pressing the epigastrium reveals hardness, or the pulse is deep and slippery, or there is anorexia with delirium (Shanyu), or the disease recurs after a specific period following recovery, these cases all involve intestinal and gastric accumulations requiring purgation. The *Neijing* states: "Severe internal heat binding causes incessant diarrhea; heat should be treated with cold, and bound pathogens must be removed using cold purgatives. Once the binding dissipates, the diarrhea stops." Conversely, "Severe internal cold stagnation causes chronic loose diarrhea, recurring over years; treat with hot purgatives. Once the cold leaves, the diarrhea stops." This is called "Tong Yin Tong Yong" (Using unblocking methods to treat unblocking symptoms).
Even if there are exterior signs in diarrhea, sweating should not be induced, because diarrhea indicates pathogens attacking inward, consuming fluids and weakening the stomach. Thus, the classics state: "Do not attack the exterior in diarrhea; inducing sweat will lead to abdominal distension." Generally, diarrhea leading to the loss of vital qi is extremely urgent. Among the "Five Deprivations" (Wuduo, five types of severe depletion), this is severe. If pathogens are strong and righteous qi is weak, with pathogens obstructing and causing righteous qi to collapse downward, death from diarrhea often ensues. Why? The classics state: "Diarrhea occurring more than ten times a day with a surprisingly strong pulse indicates death; severe fever and diarrhea with irreversible cold limbs indicate death; fixed gaze, delirium, and diarrhea indicate death; diarrhea with cold limbs and absent pulse, which do not warm with moxibustion and do not recover the pulse, indicate death; Shaoyin disease with spontaneous diarrhea, restlessness, and inability to sleep indicate death." All these cases result from pathogen obstruction and the collapse of righteous qi downward. The *Jingui Yaolue* states: "When the qi of the six fu organs fails externally, the hands and feet become cold; when the qi of the five zang organs fails internally, diarrhea becomes uncontrollable." Alas! Medicating only after the disease has formed, even a divine physician cannot save the patient. Once the qi has collapsed, who can cure it?