古人有以小儿泻痢粪黄酸臭者，皆作胃热论治，此大误也。盖饮食入胃，化而为粪，则无有不
黄，无有不臭者，岂得以黄色而酸臭者为热乎？今以大人之粪验之，则凡胃强粪实者，其色必深黄
而老苍，方是全阳正色。若纯黄不苍而粪有嫩色，则胃中火力便有不到之处，再若淡黄则近白矣。近白之色则半黄之色也，粪色半黄则
谷食半化之色也，粪气酸腥则谷食半化之气也，谷食半化，则胃中火力盛衰可知也。若必待粪青粪
白，气味不臭，然后为寒，则觉之迟矣。故但以粪色之浅深，粪气之微甚，便可别胃气阳和之成色
，智者见于未然，而况于显然乎。余故曰∶古人以粪黄酸臭为火者，大误也。再若小水之色，凡大
便泻痢者，清浊既不分，小水必不利，小水不利，其色必变，即清者亦常有之，然黄者十居八九。
此因泻亡阴，阴亡则气不化，气不化则水涸。水涸则色黄不清，此自然之理也。使非有淋热痛涩之
证，而但以黄色便作火治者，亦大误也。
小儿吐乳，虽有寒热之不同，然寒者多而热者少，虚者多而实者少，总山胃弱而然。但察其形
色脉证之阴阳，则虚实寒热自有可辨，热者宜加微清，寒者必须温补。乳子之药，不必多用，但择
其要者二、三、四味，可尽其妙，如参姜饮、五味异功散之类，则其要也。苦儿小乳多，满而溢者
，亦是常事，乳行则止不必治也。若乳母有疾，因及其子，或有别证者，又当兼治其母，宜从薛氏
之法如下。
薛氏曰∶前证若小儿自受惊，或乳母恚怒，致儿吐泻青色者，宜用异功散。若母食浓味而乳热
者，用东垣清胃散。母饮酒而乳热者，用葛花解酲汤，子服一、二匙。若饮烧酒而乳热，或子母身
赤，或昏愦，服冷米醋三、五杯，多亦无妨，儿服一、二匙。若母停滞生冷而乳冷者，母服人参养
胃汤，子服调中丸。若母停滞而变热乳者，母服大安丸，子服五味异功散。若母郁怒伤肝脾而乳热
者，用归脾汤、逍遥散。若母脾虚血弱而乳热者，用六君子加芍、归。若母气血虚而乳热者，子母
俱服八珍汤。若母劳后发热而乳热者，子母俱服补中益气汤。苦因怒动肝火而乳热者，用五味异功
散加柴胡、山栀。若吐痰涎及白绿水者，木乘脾土，虚寒证也，用六君子加柴胡、木香。大凡吐乳
泻青色者属惊，法当平肝补脾。吐泻青白色者属寒，法当温补脾土。前诸证，若手足指热者属实，
手足指冷者属虚，此亦验法也。
古人中有将小儿腹泻痢疾、粪便呈黄色且气味酸臭的情况，都按照胃热来论治，这是很大的错误。因为饮食进入胃中，消化后变成粪便，没有不黄、没有不臭的，怎么能因为粪便黄色且气味酸臭就认为是热证呢？现在用成年人的粪便来验证，凡是胃气强盛、粪便结实的人，其颜色必定是深黄而老苍，这才是全阳的正色。如果纯黄而不带苍色，且粪便有嫩色，那么胃中的火力就有不足的地方；再如果颜色淡黄，那就接近白色了。接近白色的颜色就是半黄的颜色，粪便颜色半黄就是谷食半消化的颜色，粪便气味酸腥就是谷食半消化的气味，谷食半消化，那么胃中火力的盛衰就可以知道了。如果一定要等到粪便变青变白，气味不臭，然后才认为是寒证，那发现得太迟了。所以只要根据粪便颜色的浅深，粪便气味的轻重，就可以辨别胃气阳和的状态，智者能在事情未发生前预见，何况是明显可见的呢。我所以说：古人把粪便黄且酸臭当作火证治疗，是大错特错的。再看小便的颜色，凡是大便泻痢的人，清浊既然不分，小便一定不通利，小便不通利，其颜色必然改变，即使是清稀的也常有这种情况，然而黄色的占十之八九。这是因为泻下导致阴液亡失，阴液亡失则气化不行，气化不行则水液枯竭。水液枯竭则颜色黄而不清澈，这是自然的道理。如果不是有淋证、热痛、涩滞的症状，而仅仅因为小便黄色就按火证治疗，也是大错特错的。
小儿吐乳，虽然有寒热不同，但寒证多而热证少，虚证多而实证少，总归是因为胃弱所致。只要观察其形色脉证的阴阳，那么虚实寒热自然可以辨别，热证适宜稍微清热，寒证必须温补。给婴儿用药，不必多用，只需选择重要的二、三、四味药，就能发挥其妙用，如参姜饮、五味异功散之类，就是其中的要方。如果是婴儿吃奶过多，满了溢出来的，这也是常事，乳汁通畅就会停止，不需要治疗。如果乳母有病，波及到孩子，或者有其它症状的，又应当同时治疗母亲，适宜采用薛氏的方法如下。
薛氏说：上述病症如果是小儿自己受惊，或者乳母愤怒，导致婴儿呕吐腹泻、粪便发青的，适宜使用异功散。如果母亲吃了浓味食物导致乳汁热，使用东垣清胃散。母亲饮酒导致乳汁热，使用葛花解酲汤，让婴儿服用一、两匙。如果喝烧酒导致乳汁热，或者母子身体发红，或者昏沉迷糊，服用冷米醋三、五杯，多喝也无妨，婴儿服用一、两匙。如果母亲停滞生冷食物导致乳汁冷，母亲服用人参养胃汤，婴儿服用调中丸。如果母亲停滞食物而化热导致乳汁热，母亲服用大安丸，婴儿服用五味异功散。如果母亲郁怒伤及肝脾导致乳汁热，使用归脾汤、逍遥散。如果母亲脾虚血弱导致乳汁热，使用六君子汤加芍药、当归。如果母亲气血虚弱导致乳汁热，母子都服用八珍汤。如果母亲劳累后发热导致乳汁热，母子都服用补中益气汤。如果是因愤怒触动肝火导致乳汁热，使用五味异功散加柴胡、山栀。如果呕吐痰涎以及白绿水样物，是木气乘袭脾土，属于虚寒证，使用六君子汤加柴胡、木香。大凡呕吐乳汁、腹泻粪便发青的属于惊风，治法应当平肝补脾。呕吐腹泻粪便发青白色的属于寒证，治法应当温补脾土。以上各种病症，如果手足指头热的属于实证，手足指头冷的属于虚证，这也是验证的方法。
Ancient practitioners sometimes treated cases of infants with diarrhea and dysentery, characterized by yellow and sour-smelling feces, as Stomach Heat (Wei Re). This is a significant error. When food enters the stomach and transforms into feces, it invariably becomes yellow and smelly; how can one diagnose heat solely based on yellow color and sour odor? Verification using adult feces shows that when Stomach Qi is strong and feces are solid, the color must be deep yellow and dark, representing the true color of full Yang. If the color is purely yellow without darkness and the feces appear tender, it indicates insufficient fire power in the Stomach. If the color is pale yellow, it approaches white. A color approaching white is half-yellow; half-yellow fecal color indicates partially digested grain and food; a sour and fishy fecal odor also indicates partially digested grain and food. From partially digested food, one can discern the strength or weakness of Stomach fire power. If one waits until feces turn green or white and lose their odor before diagnosing cold, the detection is too late. Therefore, by observing the depth of fecal color and the intensity of fecal odor, one can distinguish the state of harmonious Yang Qi in the Stomach. The wise perceive what has not yet occurred, let alone what is obvious. Thus, I say: treating yellow, sour-smelling feces as Fire (Huo) is a major mistake. Regarding urine color, in cases of diarrhea and dysentery, since clear and turbid fluids are not separated, urination is necessarily obstructed. When urination is obstructed, its color changes; even clear urine may occur, but yellow urine accounts for eight or nine out of ten cases. This is because diarrhea causes Yin loss; Yin loss leads to failure of Qi transformation; failure of Qi transformation leads to fluid depletion. Fluid depletion results in yellow, non-clear urine, which is a natural principle. Unless there are symptoms of stranguria (Lin Zheng), heat, pain, and astringency, diagnosing and treating yellow urine merely as Fire is also a major mistake.
Infant regurgitation of milk varies in cold and heat, but cold patterns are more common than heat, and deficiency patterns are more common than excess. Generally, this stems from weak Stomach function. By observing the Yin and Yang of physical appearance, complexion, pulse, and symptoms, deficiency/excess and cold/heat can be distinguished. For heat patterns, mild clearing is appropriate; for cold patterns, warming and tonification are essential. Medications for nursing infants need not be numerous; selecting two, three, or four key herbs can achieve excellent results, such as Shenyin (Ginseng and Ginger Drink) or Wuwei Yigong San (Five-Ingredient Powder for Supporting Vitality). These represent the key formulas. If an infant overfeeds and milk overflows, this is normal; once milk flow ceases, no treatment is needed. If the mother is ill and affects the child, or if other symptoms arise, the mother should be treated concurrently, following the methods of Xue Ji.
Xue Ji stated: If the aforementioned condition arises from the infant being startled, or from the mother's anger causing the infant to vomit and have green stools, Yigong San (Isolated Efficacy Powder) should be used. If the mother consumes rich flavors causing hot milk, Dongyuan Qingwei San (Dongyuan's Clear Stomach Powder) should be used. If the mother drinks alcohol causing hot milk, Gegua Jie Cheng Tang (Pueraria Flower Decoction to Resolve Intoxication) should be used, with the infant taking one or two spoonfuls. If the mother drinks distilled spirits causing hot milk, or if both mother and infant exhibit redness or confusion, cold rice vinegar should be consumed (three to five cups for the mother); drinking more is acceptable, and the infant takes one or two spoonfuls. If the mother consumes raw/cold foods causing cold milk, the mother should take Renshen Yangwei Tang (Ginseng Decoction to Nourish the Stomach), and the infant should take Tiaozhong Wan (Regulate Middle Pill). If the mother's stagnation turns to heat causing hot milk, the mother should take Da'an Wan (Great Peace Pill), and the infant should take Wuwei Yigong San. If the mother's depression and anger injure the Liver and Spleen causing hot milk, Guipi Tang (Restore the Spleen Decoction) and Xiaoyao San (Free Wanderer Powder) should be used. If the mother has Spleen deficiency and blood weakness causing hot milk, Liujunzi Tang (Six-Gentleman Decoction) plus Shaoyao (Peony Root) and Danggui (Angelica Sinensis) should be used. If the mother has Qi and Blood deficiency causing hot milk, both mother and infant should take Bazhen Tang (Eight-Treasure Decoction). If the mother experiences fever after exertion causing hot milk, both mother and infant should take Buzhong Yiqi Tang (Decoction to Supplement the Middle and Augment Qi). If anger stirs Liver Fire causing hot milk, Wuwei Yigong San plus Chaihu (Bupleurum Root) and Zhizi (Gardenia Fruit) should be used. If vomiting involves phlegm-saliva and white-green water, it indicates Wood encroaching on Earth (Spleen), a deficiency-cold pattern; Liujunzi Tang plus Chaihu and Muxiang (Aucklandia Root) should be used. Generally, vomiting milk and green stools indicate Shock (Jing), requiring methods to calm the Liver and tonify the Spleen. Vomiting and green-white stools indicate Cold, requiring methods to warm and tonify the Spleen and Earth. Among these conditions, hot fingertips indicate Excess, while cold fingertips indicate Deficiency; this is also a diagnostic method.