伤寒少腹满者。何以明之。少腹满者。脐下满是也。少腹者。下焦所治。难经曰。下焦
者。当膀胱上口。主分别清浊。其治在脐下。邪气自上而下。至于下焦。结而不利。故
少腹满也。胸中满。心下满。皆气尔。即无物也。及腹满者。又有燥屎为之者。至于少
腹满者。非止气也。必有物聚于此。而为之满尔。所以然者。身半以上。同天之阳。清
阳归之。身半以下。同地之阴。浊阴归之。清者在上。而浊者在下。内经谓清阳出上
窍。浊阴出下窍。当出不出。积而为满。是在上而满者气也。在下而满者物也。所谓
物者。溺与血尔。邪气聚于下焦。则津液不得通。血气不得行。或溺或血。留滞于下。
是生胀满。而硬痛也。若从心下至少腹。皆硬满而痛者。是邪实也。须大陷胸汤下
之。若但少腹硬满而痛。小便利者。则是蓄血之症。小便不利者。则是溺涩之症。经
曰。少腹满。应小便不利。今反利者。为有血也。又曰。少腹硬。小便不利者。为无血也。
小便自利。其人如狂者。血症谛也。其小便利而少腹满者。为太阳随经。瘀血在里。
太阳自入腑者也。经曰。太阳病不解。热结膀胱。其人如狂。血自下。下者愈。其外未
解者。尚未可攻。当先解外。外解已。但少腹急结者。乃可攻之。桃仁承气汤主之。是
少腹硬满。为物聚于下可知矣。渗之利之。参酌随宜。可为上工。
伤寒病出现少腹部胀满的情况，该如何阐明呢？所谓少腹满，是指脐下部位感到胀满。少腹这一区域，是由下焦所主管的。《难经》中说：下焦的位置，正当膀胱的上方，主要功能是分别清浊之气，其治疗作用范围在脐下。邪气从上向下传变，到达下焦后，凝结阻滞而不得通利，因此导致少腹胀满。胸中的胀满、心下的胀满，都是由气机阻滞引起的，即体内没有实质性的积滞物。至于腹部的胀满，又有燥结粪便作为成因。但至于少腹部的胀满，不仅仅是气的问题，必定有实物积聚在此处，从而导致胀满。之所以这样，是因为身体上半部，与天之阳气相应，清阳之气归于此处；身体下半部，与地之阴气相应，浊阴之气归于此处。清气在上，浊气在下。《内经》说：清阳出于上窍，浊阴出于下窍。当应当排出的浊阴不能排出时，积聚起来就形成了胀满。所以在上部出现的胀满是气造成的，在下部出现的胀满是实物造成的。所谓的“物”，就是溺（尿液）和血。邪气聚集在下焦，那么津液就不能通畅运行，血气也不能正常运行。或者是尿液，或者是血液，留滞于下部，从而产生胀满，甚至坚硬疼痛。如果从心下直到少腹部，都坚硬胀满且疼痛，这是邪气实盛的表现，需要用大陷胸汤来攻下它。如果只是少腹部坚硬胀满且疼痛，小便通畅的，这就是蓄血的病症；小便不利的，这就是溺涩（排尿困难）的病症。经文说：少腹部胀满，应该伴随小便不利，现在反而小便通利，说明是有瘀血存在。又说：少腹部坚硬，小便不利的，说明没有瘀血。小便自利，其人神志如狂的，是血证的确证。那些小便利而少腹部胀满的，属于太阳病随经入腑，瘀血停留在体内，这是太阳经邪气直接传入膀胱腑所致。经文说：太阳病不解，热邪结聚在膀胱，其人出现神志如狂的症状，瘀血自行下行，下行后病就好了。如果表证尚未解除，还不可以攻下，应当先解表。表证解除后，如果仅仅少腹部急迫结聚的，才可以攻下，用桃仁承气汤主治。由此可见，少腹部坚硬胀满，是由于实物积聚在下部造成的。采用渗湿或利水的方法，斟酌情况适当选用，就可以成为高明的医生了。
In the context of Cold Damage (Shanghan) disease, when there is fullness in the lower abdomen, how should this be elucidated? The term "fullness in the lower abdomen" refers to a sensation of distension below the umbilicus. The lower abdomen is governed by the Lower Jiao (Lower Burner). The *Nan Jing* (Classic of Difficult Issues) states: The Lower Jiao is located at the opening of the bladder and is primarily responsible for separating the clear from the turbid; its therapeutic domain is below the umbilicus. When pathogenic factors descend from above to the Lower Jiao, they condense and obstruct, failing to flow freely, thus causing fullness in the lower abdomen. Fullness in the chest or below the heart is caused solely by Qi stagnation, meaning there are no tangible accumulations. In contrast, abdominal fullness may be caused by dry feces. However, fullness in the lower abdomen is not merely due to Qi; it necessarily involves the accumulation of tangible matter. This is because the upper half of the body corresponds to the Yang of Heaven, where Clear Yang ascends; the lower half corresponds to the Yin of Earth, where Turbid Yin descends. Clear substances reside above, while turbid substances reside below. As stated in the *Nei Jing* (Inner Canon): Clear Yang exits through the upper orifices, and Turbid Yin exits through the lower orifices. When the turbid Yin that should be expelled fails to exit, it accumulates and causes fullness. Therefore, fullness in the upper part is caused by Qi, while fullness in the lower part is caused by tangible matter. The so-called "matter" refers to urine and blood. When pathogenic factors gather in the Lower Jiao, body fluids cannot circulate freely, and Qi and Blood cannot move smoothly. Consequently, either urine or blood remains stagnant in the lower region, generating distension, hardness, and pain. If the entire area from below the heart to the lower abdomen is hard, full, and painful, this indicates an excess of pathogenic factors, requiring the use of Da Xian Xiong Tang (Major Intractable Chest Decoction) to purge it. If only the lower abdomen is hard, full, and painful, with free urination, this is a syndrome of Blood Stasis (Xuexue); if urination is difficult, it is a syndrome of Urinary Retention (Niaose). The classics state: "When the lower abdomen is full, urination should be difficult; if it is now free, it indicates the presence of blood." It also states: "If the lower abdomen is hard and urination is difficult, it indicates the absence of blood." If urination is free and the patient exhibits mental agitation resembling madness, this is a definitive sign of a Blood Syndrome. Cases where urination is free but the lower abdomen is full indicate that the Taiyang (Greater Yang) pathogen has followed the meridians into the interior, resulting in blood stasis within the interior; this represents the Taiyang channel transmitting directly into the Bladder Fu organ. The classics state: "If Taiyang disease is not resolved, heat condenses in the Bladder, and the person becomes mentally agitated like a madman. If blood passes spontaneously, the condition resolves. If the exterior symptoms have not yet resolved, attack is not yet appropriate; one must first resolve the exterior. Once the exterior is resolved, if there is only urgency and binding in the lower abdomen, then attack is permissible, using Tao Ren Cheng Qi Tang (Peach Kernel Decoction to Direct the Qi)." Thus, it can be known that hardness and fullness in the lower abdomen result from the accumulation of tangible matter in the lower region. Employing methods of leaching or promoting diuresis, and adjusting according to circumstances, one can become a superior physician.