热结旁流，协热下利，大便闭结，大肠胶闭，总之邪在里，其证不同者，在乎通
塞之间耳。
协热下利者，其人大便素不调，邪气忽乘于胃，便作烦渴，一如平时泄泻稀粪而色不败，其
色但焦黄而已。此伏邪传里，不能稽留于胃，至午后潮热，便作泄泻，子后热退，泄泻亦减
，次日不作潮热，利亦止，为病愈。潮热未除，利不止者，宜小承气汤，以彻其余邪，而利
自止。
利止二三日后，午后忽加烦渴，潮热下泄，仍如前证，此伏邪未尽，复传到胃也，治法同前
。
大便闭结者，疫邪传里，内热壅郁，宿粪不行，蒸而为结，渐至更硬，下之结粪一行，瘀热
自除，诸证悉去。
热结旁流者，以胃家实，内热壅闭，先大便闭结，续得下利纯臭水，全然无粪，日三四度，
或十数度，宜大承气汤，得结粪而利立止。服汤不得结粪，仍下利并臭水及所进汤药，因大肠
邪胜，失其传送之职，知邪犹在也，病必不减，宜更下之。
大肠胶闭者，其人平素大便不实，设遇疫邪传里，但蒸作极臭，然如粘胶，至死不结，
但愈蒸愈闭，以致胃气不能下行，疫毒无路而出，不下即死，但得粘胶一去，下证自除，霍然
而愈。
温疫愈后三五日，或数日，反腹痛里急者，非前病原也，此下焦别有伏邪所发，欲作滞下也
。发于气分则为白积；发于血分则为红积；气血俱病，红白相兼。邪尽利止，未止者，宜芍
药汤。（方见前战汗条）
愈后大便数日不行，别无他证，此足三阴不足，以致大肠虚燥，此不可攻，饮食渐加，
津液流通，自能润下也。觉谷道夯闷，宜作蜜煎导，甚则宜六成汤。
病愈后，脉迟细而弱，每至黎明，或夜半后，便作泄泻，此命门真阳不足，宜七成汤。或亦
有杂证属实者，宜大黄丸，下之立愈。
六成汤
当归（一钱五分） 白芍药（一钱） 地黄（五钱） 天门冬（一钱） 肉苁蓉（三钱） 麦门冬（一钱）
照常煎服。日后更燥者，宜六味丸，少减泽泻。
七成汤
破故纸（炒锤碎，三钱） 熟附子（一钱） 辽五味（八分） 白茯苓（一钱） 人参（一钱） 甘草（炙，五分）
照常煎服。愈后更发者，宜八味丸，倍加附子。
热结旁流，协热下利，大便闭结，大肠胶闭，总之邪气在里，其证候的不同，在于肠道通畅与闭塞的区别罢了。
所谓协热下利，是指患者平时大便就不调畅，邪气突然侵袭胃腑，导致出现烦渴，症状如同平时的泄泻，排出稀粪且颜色没有败坏，只是呈现焦黄色而已。这是伏邪传入体内，不能滞留于胃，到了午后出现潮热，随即发生泄泻；子时之后热退，泄泻也随之减轻；第二天不再出现潮热，泄泻也停止，这表示病愈。如果潮热未除，泄泻不止，适宜使用小承气汤，以清除残余的邪气，泄泻自然停止。
泄泻停止两三天后，午后忽然又出现烦渴、潮热并伴有下泄，仍然像之前的证候，这是因为伏邪未尽，再次传变到胃所致，治疗方法同前。
大便闭结的情况，是疫邪传入体内，内热壅滞郁结，宿存的粪便无法下行，被热气蒸腾而结成硬块，逐渐变得更加坚硬。使用攻下法使结粪排出一行，瘀积的热邪自然消除，各种证候全部去除。
热结旁流的情况，是因为胃家实（胃肠实热），内热壅闭，起初是大便闭结，随后出现下利纯臭水，完全没有粪便，每天三四次，或者十几次，适宜使用大承气汤，等到结粪排出，泄泻立刻停止。如果服用汤药后没有排出结粪，仍然下利并排出臭水以及所服的汤药，这是因为大肠邪气盛极，失去了传导的功能，知道邪气仍然存在，病情必然不会减轻，适宜再次使用攻下法。
大肠胶闭的情况，是指患者平素大便就不结实，如果遇到疫邪传入体内，只是蒸腾出极其恶臭的粘液，像粘胶一样，直到死亡也不会结成硬块，但是越蒸腾越闭塞，导致胃气不能下行，疫毒无路可出，如果不进行攻下就会死亡，只要粘胶一去，下部的实证证候自然消除，病人就能豁然痊愈。
温疫痊愈后三五天，或者数天，反而出现腹痛和里急后重，这不是原来疾病的根源，而是下焦另有伏邪发作，想要形成痢疾（滞下）。发于气分则表现为白痢；发于血分则表现为红痢；气血都受病，则红白相兼。邪气尽除则泄泻停止，若未停止，适宜使用芍药汤。（方剂见前面的战汗条）
痊愈后大便几天不通，没有其他证候，这是足三阴经不足，导致大肠虚燥，这种情况不可攻下，饮食逐渐增加，津液流通，自然能够润肠通便。感觉肛门堵塞闷胀，适宜制作蜜煎导（蜂蜜栓剂）塞入肛门，严重时适宜使用六成汤。
病愈后，脉象迟细而弱，每到黎明或夜半以后，就发生泄泻，这是命门真阳不足，适宜使用七成汤。也有杂证属于实证的，适宜使用大黄丸，攻下后立即痊愈。
六成汤
当归（一钱五分） 白芍药（一钱） 地黄（五钱） 天门冬（一钱） 肉苁蓉（三钱） 麦门冬（一钱）
照常煎服。日后更加干燥的，适宜使用六味丸，稍微减少泽泻的用量。
七成汤
破故纸（炒锤碎，三钱） 熟附子（一钱） 辽五味（八分） 白茯苓（一钱） 人参（一钱） 甘草（炙，五分）
照常煎服。痊愈后再次发作的，适宜使用八味丸，加倍加入附子。
Heat-binding with peripheral flow (Re-jie Pang-liu), heat-collateral diarrhea (Xie-re Xia-li), constipation (Da-bi Bi-jie), and large intestine gel-blockage (Da-chang Jiao-bi), in summary, the pathogenic factor is in the interior. The difference in their manifestations lies merely between patency and obstruction.
Regarding heat-collateral diarrhea: The patient's bowel movements have been irregular for a long time. Suddenly, the pathogenic factor attacks the Stomach, causing irritability and thirst. The symptoms resemble usual diarrhea with loose stools that are not discolored or spoiled, but rather appear scorched yellow. This indicates latent pathogenic factors transmitting to the interior; unable to remain in the Stomach, they cause tidal fever in the afternoon, leading to diarrhea. After midnight (Zi hour), the fever subsides, and the diarrhea also decreases. If there is no tidal fever the next day and the diarrhea stops, the disease is cured. If tidal fever persists and diarrhea does not stop, Xiao Cheng Qi Tang (Minor Order the Yang Decoction) should be used to eliminate residual pathogens, after which the diarrhea will cease naturally.
Two or three days after the diarrhea stops, if irritability, thirst, tidal fever, and diarrhea suddenly recur in the afternoon, resembling the previous condition, it is because the latent pathogens are not fully cleared and have transmitted back to the Stomach. The treatment method is the same as before.
Regarding constipation: When epidemic pathogens transmit to the interior, internal heat becomes stagnant and郁 (depressed). Retained feces fail to descend, are steamed by heat into hardened masses, and gradually become harder. Once purgation causes the hardened feces to pass, the stasis-heat is removed, and all symptoms disappear.
Regarding heat-binding with peripheral flow: Due to excess heat in the Stomach and Intestines (Wei Jia Shi) and internal heat stagnation, the patient initially experiences constipation, followed by diarrhea of pure foul-smelling water without any fecal matter, occurring three to four times or even more than ten times a day. Da Cheng Qi Tang (Major Order the Yang Decoction) is appropriate. Once the hardened feces are passed, the diarrhea stops immediately. If, after taking the decoction, no hardened feces are passed, and the patient continues to excrete foul water along with the ingested medicine, it indicates that the Large Intestine is overwhelmed by pathogens and has lost its function of transportation and transformation. Knowing that the pathogen remains, the illness will not improve. Another purgative treatment is indicated.
Regarding large intestine gel-blockage: The patient usually has loose stools. Upon transmission of epidemic pathogens to the interior, the stool steams into extremely foul-smelling mucus resembling glue. It does not harden until death but becomes increasingly obstructed due to steaming. This prevents Stomach Qi from descending, trapping epidemic toxins with no exit. Without purgation, death ensues. Once the mucus is expelled, the lower excess symptoms resolve, and the patient recovers abruptly.
Three to five days or several days after recovery from warm epidemic, if abdominal pain and tenesmus (Li Ji) occur, this is not the original disease but rather latent pathogens in the Lower Jiao manifesting as dysentery (Zhi Xia). Manifesting in the Qi level results in white dysentery; manifesting in the Blood level results in red dysentery; if both Qi and Blood are affected, red and white mix. When pathogens are exhausted, diarrhea stops. If it does not stop, Shao Yao Tang (Peony Decoction) is indicated. (Formula see previous section on Battle Sweat).
Several days after recovery, if bowel movements do not occur but there are no other symptoms, this is due to insufficiency of the Three Yin Meridians of the Foot, causing deficiency-dryness in the Large Intestine. Purging is contraindicated here. As diet increases and body fluids circulate, natural lubrication and passage will occur. If there is a sensation of blockage and stuffiness at the anus, Honey Suppositories (Mi Jian Dao) should be made for local application. In severe cases, Liu Cheng Tang (Six Parts Decoction) is indicated.
After recovery, if the pulse is slow, fine, and weak, and diarrhea occurs every dawn or after midnight, this indicates insufficiency of True Yang in the Ming Men (Gate of Life). Qi Cheng Tang (Seven Parts Decoction) is indicated. There may also be mixed conditions belonging to excess patterns, for which Da Huang Wan (Rhubarb Pill) is indicated; purging will lead to immediate recovery.
Liu Cheng Tang (Six Parts Decoction)
Dang Gui (Angelicae Sinensis Radix, 1.5 qian) Bai Shao Yao (Paeoniae Radix Alba, 1 qian) Di Huang (Rehmanniae Radix, 5 qian) Tian Men Dong (Asparagi Radix, 1 qian) Rou Cong Rong (Cistanches Herba, 3 qian) Mai Men Dong (Ophiopogonis Radix, 1 qian)
Prepare and administer as usual. If dryness worsens later, Liu Wei Wan (Six-Ingredient Pill with Rehmannia) is indicated, with a slight reduction in Ze Xie (Alismatis Rhizoma).
Qi Cheng Tang (Seven Parts Decoction)
Po Gu Zhi (Cibotii Rhizoma, stir-fried and crushed, 3 qian) Shu Fu Zi (Aconiti Lateralis Radix Praeparata, 1 qian) Liao Wu Wei (Schisandrae Chinensis Fructus, 0.8 fen) Bai Fu Ling (Poria, 1 qian) Ren Shen (Ginseng Radix et Rhizoma, 1 qian) Gan Cao (Glycyrrhizae Radix et Rhizoma, honey-fried, 0.5 fen)
Prepare and administer as usual. If symptoms recur after recovery, Ba Wei Wan (Eight-Ingredient Pill) is indicated, with doubled Fu Zi (Aconiti Lateralis Radix Praeparata).