下利者，伤寒下利多属于热。热邪传里，里虚协热，亦为下利。三阳下利身热，太阴下利手足
温，少阴厥阴下利身凉无热，此其大概耳。夫自利清谷，不渴，小便色白，微寒，厥冷恶寒，脉沉
迟无力，此皆寒证也。若渴欲饮水，溺色如常，泄下黄赤，发热后重，此皆热证也。寒者，理中、
四逆汤；热者，小柴胡、猪苓汤。寒因直中阴经，热因风邪入胃，水来伤土，故令暴下。或温或攻，
或固下焦，或利小便，随证施治，但不宜发汗耳。若汗之，便邪气内攻，复泄其津液，胃气转虚，
必成胀满也。太阳阳明合病，下利，葛根汤。太阳少阴合病，下利干呕，脉实者，承气汤。太阳表
未解，数下之，遂协热利，心下痞者，桂枝人参汤。太阴自利，不渴，与夫厥逆，无脉而利者，四
逆汤。少阴咽痛，下利，胸满心烦者，猪肤甘桔汤。渴而自利纯清水，心下硬痛，口干燥者，此不
可温，急用大承气汤下之无疑矣。伤
寒，续得下利清谷，身疼痛者，急当救里，四逆汤；清便自调，急当救表，桂枝汤。下利谵语，脉
沉有力，为有燥屎，急当下之，大承气汤。肠鸣腹痛，下利，脉沉迟无力，急当温之，小建中汤。
寒毒下利而戴阳者，下虚也，附子理中汤。若夫下利谵语，目直视，下利厥冷，躁不眠，下利发热，
厥而自汗，下利厥冷，无脉，灸之不温，脉不至者，下利一日十数行，脉反实者，皆为不治也。
下利（腹泻），伤寒病中的下利多属于热证。热邪传入体内，导致里虚并夹杂热邪，也会引起下利。三阳经下利伴有身热，太阴经下利手足温暖，少阴和厥阴经下利则身体凉爽无热，这是大致的情况。如果是自发性腹泻排出未消化的食物，口不渴，小便颜色清白，轻微怕冷，四肢厥冷且恶寒，脉象沉迟无力，这些都属于寒证。如果口渴想喝水，小便颜色正常，排泄物黄赤，发热且有肛门重坠感（后重），这些都属于热证。寒证用理中汤、四逆汤治疗；热证用小柴胡汤、猪苓汤治疗。寒邪是因为直中阴经，热邪是因为风邪入胃，水气伤害脾土，所以导致突然剧烈腹泻。治疗方法或温补，或攻下，或固涩下焦，或通利小便，根据证候施治，只是不宜使用发汗法。如果误用发汗，会导致邪气内攻，进一步耗伤津液，胃气更加虚弱，必然形成胀满。太阳经与阳明经合病，出现下利，用葛根汤治疗。太阳经与少阴经合病，出现下利伴干呕，脉象实者，用承气汤治疗。太阳表证未解，多次误用泻下法，导致协热利，心下痞塞的，用桂枝人参汤治疗。太阴经自发性下利，口不渴，以及出现四肢厥逆、无脉搏而下利的，用四逆汤治疗。少阴经咽痛，下利，胸满心烦的，用猪肤甘桔汤治疗。口渴且自利排出纯清水，心下硬痛，口干燥的，这不可用温法，必须急用大承气汤攻下无疑。伤寒病，持续出现下利排出未消化食物，身体疼痛的，应当紧急救治里证，用四逆汤；大便和小便正常的，应当紧急救治表证，用桂枝汤。下利伴谵语，脉象沉而有力，是有燥屎内结，应当紧急攻下，用大承气汤。肠鸣腹痛，下利，脉象沉迟无力，应当紧急温补，用小建中汤。寒毒导致的下利且出现戴阳证（面赤如妆）的，是下元虚衰，用附子理中汤治疗。至于下利伴谵语，眼睛直视，下利伴四肢厥冷，烦躁不眠，下利伴发热且四肢厥冷却自汗，下利伴四肢厥冷且无脉搏，艾灸后不回暖，脉搏无法触及的，下利一天十几次，脉象反而实的，都属于不治之症。
Diarrhea (Xiàlì) in the context of Cold Damage (Shānghán) is mostly attributable to Heat syndromes. When pathogenic heat transmits inward, causing deficiency in the interior accompanied by heat, diarrhea also occurs. In Yangming, Taiyang, and Shaoyang syndromes, diarrhea is accompanied by fever; in Taiyin syndrome, diarrhea presents with warm hands and feet; in Shaoyin and Jueyin syndromes, diarrhea presents with a cool body and absence of fever; this constitutes the general pattern. If there is spontaneous diarrhea with undigested food in the stool, no thirst, clear urine, slight aversion to cold, cold extremities, and aversion to cold with a deep, slow, and forceless pulse, these are all Cold syndromes. If there is thirst with desire to drink water, normal urine color, yellow-red excrement, fever, and tenesmus (Hòuzhòng), these are all Heat syndromes. For Cold syndromes, Lizhong Tang (Regulate the Middle Decoction) or Sini Tang (Frigid Extremities Decoction) are used; for Heat syndromes, Xiaochaihu Tang (Minor Bupleurum Decoction) or Zhuling Tang (Polyporus Decoction) are used. Cold pathogens strike directly into the Yin meridians, while Heat pathogens enter the Stomach due to Wind pathogens; when Water Qi injures Earth (Spleen/Stomach), it causes sudden severe diarrhea. Treatments may involve warming, purging, securing the Lower Jiao, or promoting urination, applied according to the specific syndrome, but sweating methods should not be used. If sweating is induced erroneously, pathogenic factors will attack inward, further depleting Body Fluids, weakening Stomach Qi, and inevitably leading to abdominal distension. In combined Taiyang and Yangming syndromes presenting with diarrhea, Gegen Tang (Kudzu Decoction) is indicated. In combined Taiyang and Shaoyin syndromes presenting with diarrhea and dry heaving, with a full pulse, Chengqi Tang (Gastrointestinal Purge Decoction) is indicated. If the Taiyang exterior syndrome remains unresolved and repeated purgation leads to diarrhea accompanied by heat (Xié Rè Lì) and epigastric fullness/stuffiness (Xīn Xià Pǐ), Guizhi Renshen Tang (Cinnamon Twig and Ginseng Decoction) is indicated. For spontaneous Taiyin diarrhea without thirst, or for cases with cold extremities, absent pulse, and diarrhea, Sini Tang (Frigid Extremities Decoction) is indicated. For Shaoyin sore throat with diarrhea, chest fullness, and irritability, Zhufu Ganjie Tang (Pig Skin and Licorice and Platycodon Decoction) is indicated. If there is thirst, spontaneous diarrhea passing only clear water, hardness and pain in the epigastrium, and dry mouth/throat, warming methods are contraindicated; one must urgently use Dachengqi Tang (Major Gastrointestinal Purge Decoction) to purge without doubt. In Cold Damage, if continuous diarrhea with undigested food occurs alongside body pain, the interior must be urgently rescued using Sini Tang (Frigid Extremities Decoction); if bowel and bladder functions are normal, the exterior must be urgently rescued using Guizhi Tang (Cinnamon Twig Decoction). Diarrhea accompanied by delirium and a deep, forceful pulse indicates dry feces (Zào Shǐ) and requires urgent purgation with Dachengqi Tang (Major Gastrointestinal Purge Decoction). Intestinal borborygmus, abdominal pain, diarrhea, and a deep, slow, forceless pulse require urgent warming with Xiaojianzhong Tang (Minor Construct the Middle Decoction). For diarrhea caused by Cold Toxins presenting with Daiyang syndrome (floating yang/false heat on the face), indicating lower jiao deficiency, Fuzi Lizhong Tang (Aconite and Regulate the Middle Decoction) is used. As for diarrhea with delirium, fixed gaze, diarrhea with cold extremities, restlessness and insomnia, diarrhea with fever and cold extremities accompanied by spontaneous sweating, diarrhea with cold extremities and absent pulse where moxibustion fails to restore warmth and pulse, or diarrhea occurring ten or more times a day with a paradoxically full pulse, these are all untreatable conditions.