此由寒气客于经络，折于气血，血涩不通，乃结成疽发背。疽脓出之后，眼白睛青黑而
眼小，一逆也；内药而呕，二逆也；腹痛渴甚，三逆也；膊项中不便，四逆也；音嘶色
脱，五逆也。皆不可治。自余或热渴，或利呕，非仓卒之急也，可得渐治。
凡发背，则热气流入腑脏，脓溃之后，血气则虚，腑脏积热，渴而引饮，饮冷入于肠胃
，则变下痢。胃虚气逆，则变呕也。呕逆若遇冷折之，气不通即哕也。
其疮若脓汁不尽，而疮口早合，虽瘥更发，恶汁连滞，则变成 也。
此由寒气客于经络，折于气血，血涩不通，乃结成疽。疽发背，则腑脏皆热，热
则脏燥，故渴也。而冷冻饮料入肠胃，则变痢也。
肠痈者，由寒湿不适，喜怒无度，使邪气与荣卫相干，在于肠内，遇热加之，血气蕴积
，结聚成痈。热积不散，血肉腐坏，化而为脓。其病之状，小腹重而微强，抑之即痛，小便
数似淋，时时汗出，复恶寒，其身皮皆甲错，腹皮急，如肿状。诊其脉，洪数者，已有脓也
；其脉迟紧者，未有脓也。甚者腹胀大，转侧闻水声；或绕脐生疮，穿而脓出；或脓自脐中
出；或大便去脓血。惟宜急治之。
又云∶大便脓血，似赤白下，而寮非者，是肠痈也。卒得肠痈而不晓，治之错者，杀人
寸脉滑而数，滑则为实，数则为热；滑则为荣，数则为卫；卫数下降，荣滑上升；荣卫
相干，血为浊败。小腹痞坚，小便或难，汗出，或复恶寒，脓为已成。设脉迟紧，聚为瘀血
，血下则愈，家成引日。
又，诸浮数脉，当发热，而反洗淅恶寒，若有痛处者，当积有脓。脉滑涩相搏，肠痈出
《养生方》云∶六畜卒疫死，及夏病者，脑不中食，喜生肠痈也。
这是由于寒气侵入经络，导致气血运行受阻，血液涩滞不通，从而结成疽发背。在疽脓排出之后，如果出现眼白部分呈现青黑色且眼睛变小，这是第一种逆证；服药后发生呕吐，是第二种逆证；腹部疼痛且极度口渴，是第三种逆证；肩膊和颈部活动不便，是第四种逆证；声音嘶哑、面色枯槁无华，是第五种逆证。以上五种情况都属于不可治愈的危候。其余如仅有发热口渴，或伴有腹泻呕吐，并非突发急症，还可以逐渐治疗。
凡是发背疮疡，热气就会流入腑脏，脓液溃破之后，血气变得虚弱，腑脏积热，导致口渴而想饮水。如果饮用冷水进入肠胃，就会转变为下痢。胃气虚弱且气机上逆，就会转变为呕吐。如果呕吐逆气遇到寒凉药物压制，气机不通畅就会导致呃逆（哕）。
如果疮口的脓汁没有排尽，而疮口过早闭合，虽然看似痊愈但会再次发作，恶浊汁液连绵不断，就会变成漏证（瘘管）。
这也是由于寒气客居在经络，折损了气血，血液涩滞不通，从而结成疽。疽发背时，腑脏都会产生热象，热盛则脏腑干燥，所以出现口渴。如果食用冷冻饮料进入肠胃，就会转变为痢疾。
肠痈病，是由于寒湿不适，喜怒无常，导致邪气与营卫之气相互干扰，停留在肠内，再遇上热邪侵袭，血气蕴结积聚，凝聚而成痈肿。热邪积聚不散，血肉腐败坏死，化生为脓。其病症表现：小腹沉重且微微僵硬，按压即痛，小便频数似淋病，时常出汗，又怕冷，全身皮肤粗糙如鳞甲交错，腹皮紧张，像肿胀的样子。诊察其脉象，洪大且数的，说明已经有脓；脉象迟而紧的，说明还没有成脓。病情严重的会出现腹胀大，翻身转动时可听到水声；或者肚脐周围生疮，破溃后脓液流出；或者脓液直接从脐中流出；或者大便排出脓血。对此应当紧急治疗。
又说：大便排出脓血，类似赤白痢疾，但排尿不畅的，就是肠痈。突然患上肠痈而不了解病情，治疗错误的，会导致死亡。寸脉滑而数，滑脉代表实证，数脉代表热证；滑脉反映营气状态，数脉反映卫气状态；卫气之数下降，营气之滑上升；营卫相互干扰，血液变得浑浊败坏。小腹痞硬坚实，小便有时困难，出汗，或者又怕冷，说明脓已经形成。假如脉象迟而紧，说明聚积的是瘀血，瘀血下行则病愈，否则家室将长期陷入悲痛（指病人久病不愈或死亡）。
另外，各种浮数脉，通常应当发热，反而出现战栗恶寒，如果有固定痛处的，说明体内已有脓液积聚。脉象滑涩相搏，是肠痈的表现。
《养生方》说：六畜突然因疫病死亡，以及夏季患病的人，脑部不宜食用，喜欢引发肠痈病。
This condition arises from cold pathogenic qi invading the meridians and collaterals, obstructing the flow of Qi and blood. The blood becomes stagnant and unsmooth, eventually forming a carbuncle on the back (Ju Fa Bei). After the pus discharges from the carbuncle, if the whites of the eyes turn blue-black and the eyes become small, this is the first adverse sign (Ni); if vomiting occurs after taking medicine, this is the second adverse sign; if abdominal pain and extreme thirst occur, this is the third adverse sign; if the shoulders, neck, and nape are stiff and immobile, this is the fourth adverse sign; if the voice is hoarse and the complexion is sallow and devoid of luster, this is the fifth adverse sign. All these conditions are considered incurable. However, other symptoms such as fever and thirst, or diarrhea and vomiting, are not sudden emergencies and can be treated gradually.
In cases of carbuncle on the back, heat pathogenic qi flows into the Fu organs. After the pus breaks out, Qi and blood become deficient, leading to accumulated heat in the Fu organs. This causes thirst and a desire to drink. If cold drinks enter the stomach and intestines, they transform into dysentery. If Stomach Qi is deficient and rebels upward, it transforms into vomiting. If this rebellious Qi is suppressed by cold-natured medicines, causing Qi mechanism obstruction, it leads to hiccups (Yue).
If the pus within the sore is not completely drained and the wound closes prematurely, although it may appear healed, it will recur. The continuous discharge of foul fluid will transform into a fistula (Lou).
This also results from cold pathogenic qi lodging in the meridians and collaterals, damaging Qi and blood, causing blood stagnation, which forms a carbuncle. In Ju Fa Bei, all Fu organs generate heat. Excessive heat dries the Zang organs, resulting in thirst. If frozen beverages enter the stomach and intestines, they transform into dysentery.
Intestinal abscess (Chang Yong) is caused by discomfort from cold-dampness and excessive anger or joy. This allows pathogenic qi to interfere with Ying and Wei Qi, settling in the intestines. When combined with heat pathogenic qi, Qi and blood accumulate and condense to form an abscess. If the accumulated heat does not dissipate, flesh and blood rot and transform into pus. The clinical manifestations include heaviness and slight rigidity in the lower abdomen, pain upon pressure, frequent urination resembling strangury, occasional sweating, aversion to cold, rough skin resembling fish scales across the body, tense abdominal wall resembling swelling. Upon pulse diagnosis, a surging and rapid pulse indicates that pus has already formed; a slow and tight pulse indicates that pus has not yet formed. In severe cases, abdominal distension occurs, and water sounds may be heard when turning over; or sores may develop around the umbilicus, rupturing to discharge pus; or pus may discharge directly from the umbilicus; or stool may contain pus and blood. Urgent treatment is required.
It is also stated: Discharge of pus and blood in the stool, resembling red-and-white dysentery but accompanied by difficult urination, indicates intestinal abscess. If one suddenly contracts intestinal abscess without recognizing it and applies incorrect treatment, it can lead to death. A sliding and rapid pulse at the Cun position indicates excess syndrome (sliding) and heat syndrome (rapid); sliding reflects Ying Qi status, while rapid reflects Wei Qi status. Wei Qi's rapid nature descends, while Ying Qi's sliding nature ascends; their interference causes blood to become turbid and degenerated. Lower abdominal fullness and hardness, occasional difficulty in urination, sweating, or recurrent aversion to cold indicate that pus has already formed. If the pulse is slow and tight, it indicates accumulation of blood stasis. If the stasis moves downward, the disease resolves; otherwise, the family will suffer prolonged grief.
Furthermore, floating and rapid pulses typically indicate fever. If instead there is shivering and aversion to cold, along with a fixed painful area, it indicates that pus is accumulating internally. A pulse where sliding and choppy qualities interact is a sign of intestinal abscess.
The *Yangsheng Fang* states: If livestock die suddenly from epidemic diseases, or if humans fall ill in summer, consuming brain tissue is inadvisable as it predisposes one to intestinal abscess.