麻疹作痢，谓之夹疹痢，因毒热未解，移于大肠所致。有腹痛欲解，或赤或白，或赤
白相兼者，悉用清热导滞汤主之。若见痢色紫黯，或如痈脓，屋漏水，鸡肝色，黑豆汁，
气喘燥渴，发呃不食，皆不可治。若麻出之时，曾作泻痢，未经清解，至没后变成休息
痢，里急后重，昼夜无度，此余毒留于大肠，须分虚实用药。实者三黄丸利之，虚者香连
丸和之，再以黄芩汤养血行气，血和则便脓自愈，气行则后重自除，正此谓也。
麻疹大便闭者，乃火邪留结大肠，结而不解，致毒内攻，故无论前后，即与润利无妨。小水赤涩者，初起正出
时为正候，若见于正没及没后，为遗毒不散，宜用导赤散治之。如仍不通，或因大便闭结所致，通其大便，小便自利。
凡麻疹热轻，神安气安，醒睡如常吉也。设当发热正出之时，昏昏沉睡，必是火邪内郁，未透于表，速宜胜药
宣发，佐以清热，免致后患。若正没及没后见此，又是热退神清，多睡以养元复元气，不为害也。倘昏睡不省人事，
不知痛痒，或似睡非睡等症，皆在不治。又有一等面肿目闭者，乃脾经火旺，治以泻黄利水，火退，目闭自开。
麻后发热成疳，初时夜间身热自汗即退，或日晡时面红神倦嗜卧，微热得汗稍解，日复如是，宜早为施治，用黄连
解毒汤主之。倘延迟失治，或四五十日、或百日、或一二年，形体日瘦，腹膨泄泻，不可救药。
麻疹并发痢疾，称为“夹疹痢”，这是由于毒热之邪尚未解除，转移至大肠所致。如果患者出现腹痛想要排便，大便颜色或赤、或白，或赤白相兼的情况，一律使用清热导滞汤作为主方治疗。如果观察到痢疾颜色紫暗，或者像痈疽化脓的样子，呈屋漏水色、鸡肝色、黑豆汁色，并伴有气喘、烦躁口渴、呃逆、不能进食等症状，都属于不可治愈的危重症。如果在麻疹发出期间，曾经发生过泻痢，但没有经过清解治疗，等到麻疹消退后转变为休息痢（慢性痢疾），表现为里急后重，昼夜无度，这是余毒留存在大肠的缘故，必须根据虚实辨证用药。实证用三黄丸通利，虚证用香连丸调和，然后再用黄芩汤养血行气，血液调和则便脓自然痊愈，气机通畅则里急后重自然消除，说的就是这个道理。
麻疹患者出现大便闭塞不通，是因为火邪结聚在大肠，郁结不解，导致毒邪内攻，所以无论病程前后，给予润下通便的药物是没有妨碍的。小便短赤涩痛，在初起正出麻疹时属于正常脉候；如果出现在麻疹刚消退及消退之后，则是遗毒未散的表现，宜用导赤散治疗。如果小便仍然不通，可能是因为大便闭结所致，只要通利大便，小便自然通利。
凡是麻疹热势轻微，神志安宁，气息平稳，醒着和睡觉都如常，这是吉兆。假如正当发热出疹的时候，患者昏昏沉沉深度睡眠，必定是火邪内郁，未能透发于体表，应当迅速使用胜药宣发透疹，辅以清热药物，以免留下后患。如果是在麻疹刚消退及消退之后出现这种情况，又是热退神清，多睡是为了滋养元气、恢复正气，并不会造成危害。如果出现昏睡不省人事，不知痛痒，或者似睡非睡等症状，都属于不可治愈的范围。又有一类患者面部浮肿、眼睛闭合，这是脾经火旺所致，治疗应用泻黄散配合利水方法，火气消退，眼睛闭合的症状自然解开。
麻疹后退烧形成疳积，初期夜间身体发热、自汗，随后热退；或者在傍晚时分面红、神疲嗜卧，微热出汗后稍有好转，日复一日如此，应当尽早施治，以黄连解毒汤为主方治疗。如果延误失治，经过四五十天、一百天甚至一两年，患者形体日渐消瘦，腹部膨隆泄泻，就变成不可救药的绝症了。
When measles is complicated by dysentery, it is called "Measles Complicated with Dysentery" (Ma Zhen Jia Li). This is caused by toxic heat that has not yet resolved, shifting to the Large Intestine. If abdominal pain occurs with an urge to defecate, and the stool is red, white, or a mixture of both, the primary prescription should be Qing Re Dao Zhi Tang (Clear Heat and Guide Out Stagnation Decoction). If the dysenteric stool appears purple and dark, resembling pus from a carbuncle, or resembles the color of dripping roof water, chicken liver, or black bean juice, accompanied by panting, irritability, thirst, hiccups, and inability to eat, these are all intractable conditions. If diarrhea or dysentery occurred during the eruption phase of measles and was not cleared and resolved, after the measles subsided, it may transform into Resting Dysentery (Xiu Xi Li), characterized by tenesmus and frequency without limit day and night. This indicates residual toxins remaining in the Large Intestine; medication must be differentiated based on excess or deficiency patterns. For excess patterns, San Huang Wan (Three Yellows Pill) is used to purge; for deficiency patterns, Xiang Lian Wan (Aromatic and Coptis Pill) is used to harmonize. Subsequently, Huang Qin Tang (Scutellaria Decoction) is used to nourish blood and promote qi circulation. When blood is harmonized, bloody stools heal spontaneously; when qi moves freely, tenesmus is eliminated. This is the principle being described.
Constipation in patients with measles results from fire pathogens accumulating and knotting in the Large Intestine, failing to resolve, thereby causing toxic pathogens to attack internally. Therefore, regardless of whether it occurs early or late in the disease course, administering moistening and purgative herbs is harmless. Reddish and scanty urine with painful difficulty in urination is a normal manifestation during the initial eruptive stage. However, if it appears during the resolution phase or after resolution, it indicates lingering toxins that have not dispersed, and Dao Chi San (Guide Out Redness Powder) should be used for treatment. If urination remains obstructed, it may be due to fecal impaction; once the bowels are unblocked, urination will naturally flow freely.
Generally, if measles presents with mild heat, calm spirit, and steady breath, with normal waking and sleeping states, this is auspicious. However, if during the feverish eruptive stage the patient falls into a deep, lethargic sleep, it indicates internal depression of fire pathogens that have failed to vent to the exterior. It is urgent to use potent herbs to ventilate and release the exterior, assisted by heat-clearing agents, to prevent future complications. If such symptoms appear during or after the resolution of measles, but the heat has subsided and the spirit is clear, excessive sleep serves to nourish primordial qi and restore vital energy, posing no harm. Conversely, if the patient is comatose, unconscious, insensible to pain or itch, or exhibits a state of semi-consciousness, these are all intractable conditions. Another presentation involves facial swelling and closed eyes, which is caused by flourishing fire in the Spleen Meridian. Treatment should employ Xie Huang San (Drain Yellow Powder) combined with diuretic methods; once the fire recedes, the eye closure will naturally resolve.
Post-measles fever leading to Gan syndrome (malnutrition syndrome) initially presents with nocturnal body heat and spontaneous sweating, which then subside. Or, in the late afternoon, there is facial flushing, mental fatigue, drowsiness, slight fever relieved by sweating, repeating daily. Early intervention is required, primarily using Huang Lian Jie Du Tang (Coptis Decoction for Resolving Toxicity). If treatment is delayed or neglected, over a period of forty to fifty days, one hundred days, or even one to two years, the patient's physique becomes increasingly emaciated, the abdomen distends, and diarrhea persists, rendering the condition incurable.