痘疮腹胀之证，其要有二∶一以脾胃受伤，一以邪气陷伏。盖痘疮将发，毒由内生，
其证无不发热或见微渴，此其常也。当此之时，只宜温平和解，或兼托散，怃抑遏，无穷追，
无残及元气，惟贵轻扬善导，但令毒透肌表，则苗秀而实，无不善矣。设不知此，而见热即退热，
见毒即攻毒，则未有妄用寒凉而不伤胃气者，未有但知攻毒而不伤元气者。胃气伤则营运无力
而脾寒，所以作胀，元气伤则托送无力而毒陷，所以作胀。虽作胀之由，犹不止此，然惟此最
多，而人多不能察也。诸未尽者，俱详如下。
一、误服凉药或过食生冷而作胀者，其人必不能食，或大小便利，或腹中雷鸣，此皆脾胃
中寒之证，速宜温中以疏逐冷气，冷气散则胀自消矣，宜益黄散加姜制浓朴，或人参胃爱散
加干姜。若胃寒兼虚，疮白神倦，或气促发厥者，惟温胃饮及陈氏十一味木香散俱为要药。
若寒在脾肾，下焦不化而作胀者，非理阴煎不可。
一、中气本虚，或过用消伐，以致元气无力，不能托送痘毒而陷伏作胀者，宜十宣散，
或合二妙散或神香散。
一、痘毒陷伏于里者，必有热证相杂，如烦躁干渴，大小便秘而作胀者，此只宜温平快气兼
托之剂，当用紫草饮子。
一、寒邪外闭肌腠，身热无汗，或气喘鼻塞，则痘毒不能外达而陷伏腹胀者，宜五积散，
或加减参苏饮。
一、饮食过伤，偶为停滞而腹胀者，此不过一时之滞，食去则胀消，宜大和中饮，或合二妙
散、神香散。
一、腹胀而目闭，口中如烂肉臭，或大便泄泻，或利脓血者，皆不治。
The syndrome of abdominal distension in smallpox has two main causes: one is injury to the Spleen and Stomach, and the other is the sinking and entrapment of pathogenic factors. Generally, when smallpox is about to erupt, the toxin arises from within the body. The symptoms invariably include fever or slight thirst; this is the normal presentation. At this time, only mild and harmonious methods should be used for resolution, or combined with methods to support and expel toxins. One must avoid suppressive treatments, ceaseless aggressive attacks, and harming the Yuan Qi (Primordial Qi). It is most valuable to use light, ascending, and guiding methods, ensuring that the toxin penetrates to the muscle surface. If this is achieved, the pustules will develop properly and heal well. However, if one fails to understand this and merely treats fever by clearing heat or treats toxins by attacking them directly, there will inevitably be cases where the misuse of cold-cooling herbs damages Stomach Qi, and cases where focusing solely on attacking toxins damages Yuan Qi. When Stomach Qi is injured, transportation and transformation become weak, leading to Spleen Cold, which causes distension. When Yuan Qi is injured, the ability to push out toxins becomes weak, causing toxins to sink, which also causes distension. Although there are other causes for distension, these two are the most common, yet people often fail to discern them. Other remaining conditions are detailed below.
1. Distension caused by mistakenly taking cooling medicines or overeating raw and cold foods: The patient will certainly have poor appetite, or normal bowel and urinary functions, or borborygmus (rumbling in the intestines). These are all signs of Cold in the Spleen and Stomach. One should quickly warm the Middle Jiao to disperse and drive out Cold Qi. Once the Cold Qi disperses, the distension will subside naturally. Yi Huang San (Yellow Benefit Powder) added with Ginger-processed Houpo (Magnolia Bark) is suitable, or Ren Shen Wei Ai San (Ginseng Stomach Love Powder) added with Ganjiang (Dried Ginger). If there is Stomach Cold combined with deficiency, manifested by pale pustules, mental fatigue, shortness of breath, or syncope, Wen Wei Yin (Warm the Stomach Decoction) and Chen Shi Shi Yi Wei Mu Xiang San (Mr. Chen’s Eleven-Ingredient Costus Powder) are both essential remedies. If the Cold is in the Spleen and Kidney, and the Lower Jiao fails to transform, causing distension, Li Yin Jian (Regulate Yin Decoction) is indispensable.
2. Distension caused by inherent deficiency of Middle Qi, or excessive use of draining and reducing methods, resulting in weak Yuan Qi that cannot support the expulsion of smallpox toxins, leading to their sinking and entrapment: Shi Xuan San (Ten-Auspicious Powder) is suitable, or it can be combined with Er Miao San (Two-Wonder Powder) or Shen Xiang San (Aromatic Incense Powder).
3. Smallpox toxins sinking and entraping inside the body: This must be mixed with Heat syndromes, such as restlessness, dry mouth, and thirst, constipation of stool and urine, causing distension. In this case, only mild, harmonious, qi-regulating, and supporting formulas should be used. Zi Cao Yin (Arnebia Drink) should be employed.
4. External closure of skin and pores by Cold pathogens, presenting with fever, absence of sweating, wheezing, or nasal congestion, causing smallpox toxins to fail to reach the exterior and instead sink and entrap, leading to distension: Wu Ji San (Five Accumulations Powder) or Jia Jian Shen Su Yin (Modified Ginseng and Perilla Leaf Decoction) are suitable.
5. Distension caused by dietary excess leading to temporary stagnation: This is merely a momentary stagnation; once the food residue is removed, the distension will disappear. Da He Zhong Yin (Great Harmonize the Middle Drink) is suitable, or it can be combined with Er Miao San (Two-Wonder Powder) or Shen Xiang San (Aromatic Incense Powder).
6. Abdominal distension accompanied by closed eyes, foul odor in the mouth resembling rotting meat, diarrhea, or passage of pus and blood: These are all untreatable conditions.