寒热交作，起迄有时谓之疟。赤白利下，里急后重谓之痢。疟疾有似乎寒热，然寒热之止作无定，内伤
外感，并皆有之，与疟疾之由寒而热，一日一作，二日一作，或三日一作者迥不相同也。痢疾有似乎泄泻，然
泄之或多或少，或清或稀，皆有臭秽污水杂出其间，与痢疾之粘液似冻，类脓非脓，类血非血，赤白相
间，欲下不下，里急后重者，迥不相同也。此二证者，虽四季皆有，而独盛于夏秋，则以夏秋之天时，转变
靡常，时令之偏胜，酿 时邪亦最盛，而人当此期，正精神疲惫，肠胃薄弱之际，卫气最易失守，故时邪得
而乘之也。二证之起因，虽皆由时邪，然因所感之不同，及受处之各异，证状遂为悬殊，疟疾所感为风气
之邪，受处为营卫之间，故其病为阴阳交并，寒热交争；痢疾所感为湿气之邪，受处为肠腑之间，故其病为
传化失职，郁蒸滞下。不仅此也，同一疟证，因身体不同居处不同感受之深浅不同，而疟遂有多端，病浅者发
于三阳，病深者发于三阴，久疟则成疟母而不时发作；同一痢证，因身体不同、居处不同、感受之深
浅不同，而痢遂有多端，病浅者赤白滞下，病深者发热不休，久痢则成休息而不时发作。凡疟、痢之经久，
邪动则病，邪伏则已，正气不能伸张，病邪留舍不去，于是疟、痢两证，遂为四季皆有之病矣。又疟之为病，
可藉饮食物及蚊虫为传染，痢之为病，可藉饮食物及粪便为传染，甚者则感其气息而亦病，沿门阖境，谓
之疫疟、疫痢焉。其病成人患之，已觉亏乏，小儿感染，倍觉困顿。兹因其证虽不同，而其起伏之处，颇
有似之者，故同类而共论之。
寒热交替发作，且有固定的起止时间，这称为疟。大便排出赤白脓血，伴有腹部急迫、肛门重坠感，这称为痢。疟疾的症状似乎与寒热往来相似，然而普通寒热的发作没有固定规律，无论是内伤还是外感都可能出现，这与疟疾由寒转热，或每日发作一次、隔日发作一次、甚至三日发作一次的规律截然不同。痢疾的症状似乎与泄泻相似，然而泄泻的大便量或多或少，质地或清或稀，其中混杂着有臭味的污水；而痢疾则是排出粘液状如冻胶，看似脓液却非真脓，看似血液却非真血，红白相间，想排便却排不出，腹部急迫、肛门重坠，两者完全不同。这两种病症，虽然一年四季都有发生，但在夏秋两季最为盛行，这是因为夏秋季节气候多变，时令之气偏胜，导致时行邪气（季节性致病因素）最盛，而人在此时正值精神疲惫、肠胃薄弱之际，卫气（防御外邪的气）最容易失守，所以时行邪气得以乘虚而入。这两种病的起因，虽然都是由时行邪气引起，但由于感受的邪气不同，以及受邪的部位各异，症状表现就相差悬殊：疟疾所感受的是风气之邪，受邪部位在营卫之间，所以其病机是阴阳交并、寒热交争；痢疾所感受的是湿气之邪，受邪部位在肠腑之间，所以其病机是传化功能失职，湿热郁蒸导致滞下。不仅如此，同样是疟证，因为体质不同、居住环境影响、感受邪气的深浅不同，疟疾的表现就有多种多样：病位浅的发作在三阳经，病位深的发作在三阴经，久疟则形成疟母（脾脏肿大），且发作不定时；同样是痢证，因为体质不同、居住环境影响、感受邪气的深浅不同，痢疾的表现也有多种多样：病位浅的表现为赤白滞下，病位深的表现为发热不退，久痢则成为休息痢（时发时止的慢性痢疾），且发作不定时。凡是疟疾、痢疾经久不愈，邪气动则发病，邪气伏则病止，正气不能伸展张扬，病邪留滞不去，于是疟疾和痢疾就成了四季都可能发生的疾病了。另外，疟疾这种病，可以通过饮食物和蚊虫叮咬进行传染；痢疾这种病，可以通过饮食物和粪便进行传染，严重的甚至通过呼吸气息也能感染，沿着门户遍及全境，这就称为疫疟、疫痢。这些病如果是成人患病，已经觉得身体亏乏虚弱，小儿如果感染，更是加倍感到困顿衰弱。现在因为它们的症状虽然不同，但在起伏变化的特点上颇有相似之处，所以将同类病症放在一起共同论述。
Alternating chills and fever with regular onset and cessation are termed *Nüe* (Malaria). The passage of red and white dysenteric stools accompanied by tenesmus is termed *Li* (Dysentery). Malaria symptoms may resemble alternating chills and fever, yet the latter lack a fixed pattern; both internal injury and external contraction can cause them, which is distinctly different from malaria where chills precede fever, occurring daily, every other day, or every third day. Dysentery symptoms may resemble diarrhea, yet diarrhea involves varying amounts of stool, either clear or loose, mixed with foul-smelling watery excrement. In contrast, dysentery involves discharge of mucus resembling jelly, pus-like but not true pus, blood-like but not true blood, with red and white strands intermixed, characterized by the urge to defecate without success and severe tenesmus; these two conditions are entirely different. Although both conditions occur throughout the year, they peak in summer and autumn. This is because during these seasons, weather changes frequently, seasonal qi becomes excessive, leading to the prevalence of epidemic pathogens (seasonal pathogenic factors). At this time, people are often mentally exhausted and their intestines and stomachs are weak, making Wei Qi (Defensive Qi) prone to failure, allowing epidemic pathogens to invade. Although both diseases originate from epidemic pathogens, differences in the specific pathogens contracted and the sites of invasion lead to vastly different symptoms: Malaria is caused by Wind Qi, invading between Ying (Nutritive) and Wei (Defensive) levels, resulting in the intermingling of Yin and Yang and the struggle between cold and heat; Dysentery is caused by Dampness Qi, invading the Intestines and Bowels, resulting in the failure of transportation and transformation, and stagnation due to damp-heat steaming. Furthermore, even within the same category of Malaria, variations in constitution, living environment, and depth of pathogen invasion lead to diverse manifestations: superficial cases manifest in the Three Yang channels, deep cases in the Three Yin channels, and chronic malaria may develop into *Nuomu* (Malarial Mass/Splenomegaly) with irregular attacks. Similarly, for Dysentery, variations in constitution, environment, and depth of invasion lead to diverse forms: superficial cases present with red and white dysenteric stools, deep cases with persistent fever, and chronic dysentery may become *Xiuxi Li* (Intermittent Dysentery) with irregular attacks. For prolonged malaria and dysentery, when pathogens move, disease manifests; when pathogens hide, disease subsides. If Zheng Qi (Upright Qi) cannot expand and pathogens remain lodged, these conditions become illnesses that can occur in any season. Additionally, Malaria can be transmitted via food, drink, and mosquito bites; Dysentery can be transmitted via food, drink, and feces. Severe cases can even be transmitted through respiratory droplets, spreading throughout communities, termed Epidemic Malaria (*Yi Nüe*) and Epidemic Dysentery (*Yi Li*). When adults contract these diseases, they feel depleted; when children contract them, they feel doubly distressed. Since the clinical presentations differ but the patterns of progression and fluctuation are similar, these related conditions are discussed together here.