凡诸病以小水少，则病益进。至于痘疮，正当君火用事，是以心移热于小肠，小
肠移热于膀胱，膀胱虽为津液之腑，必由肺气之输化而始出。若气为火蚀，则失降下之
令，故小便秘涩，则热毒无以走泄，发惊发搐，势所必来，治又不可骤用凉药，当利小
便，以导去之。小热不去，则大热必生也。若痘稠密而小便赤少者，此因津液耗损，下
焦少血也。不可妄利，反损真阴，徒增为喘、为渴之端。更有积痰在肺，肺为上焦，
膀胱为下焦，因上焦闭，而下焦乃塞者，治宜清肺，犹滴水之物，上窍通而下窍乃出，
故古方利水剂中，加以荆芥，或用吐法，并此意也。更有气结于下而乃小便不通者，治
直升之，盖气升行，而水自降下，然汗下利三者，古人并重用之，一妄皆可损人也。
夫诸腹痛多属于寒，独痘疹腹痛，多属于火，虽然尤宜细详。如身不甚热，口不作
渴，时或发寒，时或呕吐，肠鸣自利，六脉虚细，面青手足冷，而属脾胃虚寒者，宜温
补之。如面赤作渴，手足热，而属脾胃实热者，宜微损之。如不思乳食，嗳腐吞酸，而
系伤食作痛者，宜内消之。如出不快，而有陷伏作痛，烦躁啼叫者，宜急表暴之。如大
便秘结，而谵妄狂乱，有燥粪而痛苦，宜微下之。如误食生冷而冷痛者，则投温剂以消
之。如感冒风寒，与毒相并，致未尽出，而身体战动作痛者，宜发散之。如腹痛而热毒
在胃，时欲呕吐者，则清解之。如疮乍出乍隐，手足发厥有伏而痛者，宜大托之。若不
出者，勿治。如靥后多热，大便坚实，粪黑腹痛者，此蓄血也，宜清利之。至若气粗口
臭，唇舌白苔，身发战动，作痛不已者，此必风寒阻隔，阴阳壅塞不通，毒归脏腑，已
成内溃，而胃烂成脓矣。更有毒瓦斯弥蔓，阳毒入胃，是以便血无度，腹痛啼哭者，并发
热时，心腹绞痛，烦闷叫号，其疮陷伏，而胀满疼痛喘促者，此皆毒恶之气攻刺肠胃，
燔灼脏腑，至恶之候也，并不可治。然凡延绵痛而无止者，寒也。时痛时止者，热也
凡是各种疾病，如果小便量少，病情就会加重。至于痘疮（天花），正值心火当令之时，因此心将热邪移于小肠，小肠再将热邪移于膀胱。膀胱虽然是贮存津液的腑，但必须依靠肺气的输布和转化才能排出尿液。如果气被火热灼伤，就失去了向下通降的功能，所以小便不通畅涩滞，导致热毒无法通过小便排泄出去，进而引发惊厥抽搐，这是必然的趋势。治疗时又不可突然使用寒凉药物，应当通利小便，引导热邪排出。如果轻微的热邪不去除，那么严重的大热一定会产生。如果痘疹稠密且小便颜色红赤、量少，这是因为津液耗损，下焦血液不足。此时不可盲目利尿，否则会反而损伤真阴，徒然增加气喘、口渴等症状的根源。更有积痰停留在肺部，肺位于上焦，膀胱位于下焦，因为上焦闭塞，所以下焦也就堵塞了，治疗应当清肃肺气，这就像滴水器一样，只有上面的孔窍通了，下面的水才会流出，所以古方中利水的药剂里，加入荆芥，或者采用催吐法，都是基于这个原理。更有因气机郁结在下焦而导致小便不通的，治疗应当提升气机，因为气机上升运行，水液自然就会下降排出。然而，发汗、攻下、利尿这三种治法，古人非常重视并谨慎使用，一旦误用都会损害人体。
至于各种腹痛大多属于寒证，唯独痘疹引起的腹痛，大多属于火证，虽然如此，尤其需要仔细详察。例如身体发热不明显，口不干燥想喝水，时而怕冷，时而呕吐，肠鸣腹泻，六脉虚弱细微，面色青白，手脚冰冷，这属于脾胃虚寒，适宜用温补法治疗。例如面色发红，口干想喝水，手脚发热，这属于脾胃实热，适宜用轻微泻下的方法治疗。例如不想吃奶或食物，打嗝有腐臭味，吞酸，这属于饮食积滞引起的疼痛，适宜用内消导滞的方法治疗。例如痘疹出不顺畅，且有内陷伏匿引起的疼痛，伴有烦躁啼哭，适宜紧急使用解表透疹的方法。例如大便秘结，胡言乱语，狂躁混乱，有燥屎积聚而痛苦，适宜轻微攻下。例如误食生冷食物导致冷痛，则投以温热药剂来消除它。例如感冒风寒，与毒邪相合并，导致痘疹未能完全发出，身体颤抖作痛，适宜发散解表。例如腹痛且热毒在胃，时常想要呕吐，则清热解之。例如痘疮忽出忽隐，手脚发凉，有伏匿而疼痛，适宜大力托毒外出。如果痘疹完全不出的，不要治疗。例如结痂后多热，大便干硬，粪便黑且腹痛，这是瘀血蓄积，适宜清热利湿化瘀。至于呼吸粗重，口臭，嘴唇舌头有白色苔垢，身体发抖，疼痛不止，这一定是风寒阻隔，阴阳壅塞不通，毒邪归入脏腑，已经形成内部溃烂，胃腐烂成脓了。更有毒气弥漫，阳毒进入胃，导致便血无度，腹痛啼哭，并发热时，心腹绞痛，烦闷呼叫，痘疮内陷伏匿，腹胀满疼痛且气喘急促，这都是恶毒之气攻刺肠胃，焚烧灼烧脏腑，是最恶劣的征候，都不可治愈。然而，凡是绵延不断的疼痛而没有停止的，是寒证；时痛时止的，是热证。
In all diseases, if the volume of urine is low, the condition will worsen. Regarding smallpox (Xiaochuan), it occurs when Heart Fire is dominant; thus, Heat transfers from the Heart to the Small Intestine, and from the Small Intestine to the Bladder. Although the Bladder is the Fu-organ responsible for storing fluids, its urination depends on the distribution and transformation by Lung Qi. If Qi is scorched by Fire, it loses its descending function, leading to scanty and difficult urination. Consequently, Heat-Toxin cannot be excreted through urine, inevitably leading to convulsions and spasms. Treatment should not abruptly use cold-natured medicines; instead, one should promote diuresis to guide out the Heat. If mild Heat is not resolved, severe Heat will certainly arise. If the rash is dense and urine is red and scanty, this is due to fluid depletion and blood deficiency in the Lower Jiao. Blind diuresis should be avoided, as it would damage True Yin and merely exacerbate symptoms such as panting and thirst. Furthermore, if accumulated Phlegm resides in the Lungs, and since the Lungs are in the Upper Jiao while the Bladder is in the Lower Jiao, blockage in the Upper Jiao causes obstruction in the Lower Jiao. The treatment should focus on clearing the Lungs. This is analogous to a water-dropping device: only when the upper orifice is open does the water flow from the lower orifice. Therefore, ancient diuretic formulas often include Jingjie (Schizonepetae Herba) or employ emetic methods, based on this principle. Additionally, there are cases where urinary retention is caused by Qi stagnation in the Lower Jiao; these should be treated by raising Qi, as when Qi ascends and moves, Water naturally descends. However, sweating, purging, and diuresis are three methods highly valued and used cautiously by ancients; misuse of any can harm the body.
Regarding abdominal pain, most cases belong to Cold, but abdominal pain associated with smallpox mostly belongs to Fire. Nevertheless, careful differentiation is required. For instance, if the body has little fever, there is no thirst, occasional chills occur, vomiting happens intermittently, borborygmus and spontaneous diarrhea are present, the six pulses are weak and fine, the complexion is cyanotic, and hands and feet are cold, this indicates Spleen-Stomach Deficiency-Cold, which is suitable for warming and tonification. If the face is red, there is thirst, and hands and feet are hot, this indicates Spleen-Stomach Excess-Heat, which is suitable for mild purgation. If there is an aversion to milk or food, belching with a putrid odor, and acid regurgitation, indicating pain due to Food Stagnation, internal resolution via digestion-promoting methods is appropriate. If the eruption is slow and accompanied by sinking/retention pain, restlessness, and crying, urgent exterior-releasing and eruption-promoting methods are needed. If there is constipation, delirium, mania, dry feces accumulation causing pain, mild purgation is indicated. If cold pain results from ingesting raw/cold foods, warm formulas should be administered to resolve it. If Wind-Cold invasion combines with Toxin, preventing complete eruption, causing tremors and pain, dispersing and releasing the exterior is appropriate. If abdominal pain occurs with Heat-Toxin in the Stomach and frequent nausea, clearing and resolving Heat is indicated. If lesions appear and disappear intermittently, with cold extremities and retentive pain, strong support for expelling Toxin is required. If lesions do not erupt at all, no treatment is applied. After scabbing, if there is excessive heat, hard stools, black stool, and abdominal pain, this indicates Blood Stasis, suitable for clearing Heat and promoting diuresis to remove stasis. If breathing is coarse, there is foul breath, white coating on lips and tongue, body tremors, and unceasing pain, this indicates Wind-Cold obstruction, blocking Yin and Yang, with Toxin entering the Zang-Fu organs, leading to internal ulceration and gastric rot/pus formation. If Toxic Miasma spreads widely, Yang-Toxin enters the Stomach, causing profuse bloody stool, abdominal pain, and crying, accompanied by fever, heart/abdominal colic, distress, screaming, sunken lesions, abdominal distension, pain, and panting, these are signs of malignant Qi attacking the intestines and stomach, burning the Zang-Fu organs—extremely adverse conditions that are untreatable. However, continuous pain without cessation indicates Cold; intermittent pain indicates Heat.