夫痘疹腹痛者，由热毒郁于三阴，滞于肠胃，脐以上属太阴，当脐属少阴，小腹属
厥阴，须分别之，治法俱当升发解利。痘毒兼分利小便，使毒瓦斯上下分消，则痛自止。
故《内经》所论腹痛，皆属于寒。惟疮疹初热腹痛，则是其毒在内攻动，所发皆属热
毒，然亦有虚实之分。如肠鸣自利而腹痛者为虚，虚即是冷也。如发热烦躁作渴。饮冷
腹满不大便而腹痛者为实，实即是热也，虽有肢体厥冷之症。所谓热深厥亦深耳。宜急
托里使毒瓦斯达于表，则脏腑气和，四肢温暖，腹痛自止矣。
痘疮发热而先腰痛者，最忌症也。《经》曰∶腰者，肾之府也。又曰∶太阳所至为腰
痛，盖足太阳膀胱为十二经之首，其脉侠脊而入循膂络肾。夫痘疮之毒，起于右肾之
下，而循足太阳膀胱，散于诸经，出里以传表也。如初热而腰即痛，则邪由膀胱直入于
肾，故关节不利，乃腰痛耳。其治宜亟解毒以泻少阴之邪，亟发表以逼太阳之经，使邪
气不得深入，则疮虽稠密，或可愈也，治若少缓，则太阳之邪，由表以传于阳，少阴之
邪，由里以传于阴，表里受病，阴阳俱伤，而荣卫之脉不行，脏腑之气皆绝，是以或为
不出，或为痒塌，或为黑陷，终莫救矣。更有因肾经虚怯，相火内烁，是以真阴不得胜
邪，故乃腰痛者，初宜升发达表，俟其出后，即与地黄丸料，以防变黑归肾，乃克有
济，此痘多因禀赋肾家精气不足，谓之折腰痘是也。故凡平素面白，或时面赤，眼白睛
多，言语皆迟，频患颈痛，尺脉洪数，足冷腰痛，或足热发渴者，皆是肾虚，并宜预为
调补也。腰主于肾，人之一大关节也。血气流通则平，血疑气滞则痛，肾实则屈伸壮，
肾虚则屈伸难，故腰疼痘之切忌也。然初热痛者，是蕴毒初动，火热亢极，肾水有亏，
乃腰疼耳。此则，治宜升发而养清凉解毒。若症由干枯，宜即养血，若肾大虚而痛者，
尤宜倍加滋阴补肾之剂，至如治之而不愈，反兼胸高足冷者，则肾败毒，深必难救也。
然男子成婚破阳之后，出痘腰痛者可疗，以其虚于后天也。若童子腰痛难治，乃先天之
水不足，为真虚也。
凡是痘疹出现腹痛的，是由于热毒郁结在三阴经，阻滞在肠胃。脐以上部位属于太阴经，正对肚脐的部位属于少阴经，小腹部位属于厥阴经，必须加以区分。治疗方法都应当采用升发透邪、疏利气机的方法。治疗痘毒时兼用分利小便的方法，使毒气上下分散消除，疼痛自然停止。所以《内经》中论述的腹痛，大多归属于寒证。只有疮疹初起发热时的腹痛，是因为毒邪在内攻动所致，所发的病证都属于热毒，然而也有虚证和实证的区分。例如肠鸣、自发性腹泻且腹痛的属于虚证，虚证就是冷证。例如发热、烦躁、口渴想喝冷饮、腹部胀满、大便不通且腹痛的属于实证，实证就是热证，即使有四肢冰冷的症状，这也是所谓的“热深厥亦深”（内热越盛，四肢厥冷越严重）。应当紧急使用托里透毒的方法，使毒气达于体表，那么脏腑之气调和，四肢温暖，腹痛自然停止。
痘疮发热而首先出现腰痛的，是最忌讳的症状。《内经》说：“腰是肾的外府。”又说：“太阳经气异常会导致腰痛。”这是因为足太阳膀胱经是十二经脉之首，其经脉夹着脊柱进入，沿着背部肌肉联络肾脏。痘疮的毒邪，起源于右肾之下，沿着足太阳膀胱经运行，散布于各条经脉，由里出表进行传变。如果在初热阶段腰部就疼痛，说明邪气从膀胱直接侵入肾脏，导致关节活动不利，这就是腰痛。治疗应当紧急解毒以泻除少阴经的邪气，紧急发表以驱逐太阳经的邪气，使邪气不能深入体内，那么即使痘疮稠密，或许可以痊愈。如果治疗稍有迟缓，太阳经的邪气就会由表传入阳分，少阴经的邪气就会由里传入阴分，导致表里同时受病，阴阳俱伤，营卫之脉的运行停滞，脏腑之气断绝，因此有的痘出不出来，有的出现瘙痒塌陷，有的出现黑陷，最终无法挽救了。更有因为肾经虚弱怯懦，相火在内灼烧，导致真阴不能战胜邪气，从而引起腰痛的，初期应当先升发达表，等到痘疹发出后，立即给予地黄丸的药物组成，以防止病情变为黑陷归肾，这样才能有所救助。这痘症多是因为禀赋中肾家精气不足，称为折腰痘。所以凡是平时面色苍白，或者时而面色发红，眼白部分较多，说话迟缓，频繁患颈部疼痛，尺脉洪大数急，脚冷腰痛，或者脚热发渴的，都是肾虚的表现，都应当预先进行调补。腰由肾主宰，是人体的一大关节。气血流通则平安无事，血瘀气滞则疼痛，肾气充实则屈伸有力，肾虚则屈伸困难，所以腰痛对于痘症来说是极其忌讳的。然而初热时疼痛的，是蕴藏的毒邪刚刚发动，火热亢盛到了极点，肾水亏损，从而导致腰痛。这种情况，治疗应当升发并配合养阴凉血解毒。如果症状由干枯引起，应当立即养血；如果肾虚严重而疼痛的，尤其应当加倍增加滋阴补肾的药物。至于治疗不愈，反而兼见胸部高耸、脚冷的，则是肾败毒深，必定难以救治。然而男子在成婚破阳之后，出痘出现腰痛的可以治疗，因为这是后天之虚。如果是童子腰痛难治，乃是先天之水不足，属于真正的虚损。
In cases where smallpox or chickenpox presents with abdominal pain, it is caused by heat-toxin stagnating in the Three Yin meridians and obstructing the intestines and stomach. The area above the umbilicus belongs to the Taiyin meridian, the area directly at the umbilicus belongs to the Shaoyin meridian, and the lower abdomen belongs to the Jueyin meridian; these must be distinguished. The treatment method for all should involve ascending and releasing pathogenic factors while promoting free flow. When treating the toxin of smallpox/chickenpox, one should concurrently employ methods to promote urination, allowing the toxic qi to disperse both upward and downward, after which the pain will cease naturally. Therefore, the abdominal pain discussed in the *Neijing* (Classic of Internal Medicine) is generally attributed to cold patterns. However, abdominal pain occurring during the initial fever stage of sores and rashes is due to internal toxins attacking and moving; such eruptions are all attributed to heat-toxins. Nevertheless, there are distinctions between deficiency and excess patterns. For instance, intestinal borborygmus, spontaneous diarrhea accompanied by abdominal pain indicates a deficiency pattern, where deficiency equates to cold. Conversely, fever, irritability, thirst with a desire for cold drinks, abdominal fullness, constipation, and abdominal pain indicate an excess pattern, where excess equates to heat. Even if symptoms of cold limbs appear, this is what is referred to as "the deeper the heat, the deeper the cold extremities" (severe internal heat leads to severe peripheral cold). One should urgently employ methods to support the interior and expel toxins to the surface, thereby harmonizing the Qi of the Zang-Fu organs and warming the limbs, after which the abdominal pain will cease.
When fever from smallpox/chickenpox is preceded by lumbar pain, it is a most ominous sign. The *Jing* (Scripture) states: "The waist is the mansion of the Kidney." It also states: "Abnormalities of the Taiyang lead to lumbar pain." This is because the Foot-Taiyang Bladder Meridian is the head of the twelve meridians; its channel runs alongside the spine, enters along the back muscles, and connects with the Kidney. The toxin of smallpox/chickenpox originates below the right Kidney, follows the Foot-Taiyang Bladder Meridian, disperses through various meridians, and transmits from the interior to the exterior. If lumbar pain occurs immediately during the initial fever stage, it indicates that the pathogen has entered the Kidney directly from the Bladder, causing joint stiffness and resulting in lumbar pain. Treatment should urgently clear toxins to drain the Shaoyin pathogen and urgently release the exterior to drive out the Taiyang pathogen, preventing the pathogen from penetrating deeply. In this way, even if the eruption is dense, recovery may be possible. If treatment is delayed even slightly, the Taiyang pathogen will transmit from the exterior to the Yang aspect, and the Shaoyin pathogen will transmit from the interior to the Yin aspect. This results in simultaneous disease of the interior and exterior, injury to both Yin and Yang, cessation of Ying-Wei circulation, and exhaustion of Zang-Fu Qi. Consequently, eruptions may fail to emerge, or present with itching and collapse, or black depression, ultimately becoming incurable. Furthermore, lumbar pain may arise from weakness and deficiency of the Kidney Meridian, with Minister Fire scorching internally, causing True Yin to be unable to overcome the pathogen. Initially, one should employ ascending and releasing methods to open the exterior. After the eruption appears, one should immediately administer formulas based on Dihuang Wan (Rehmannia Pill) to prevent progression to black depression returning to the Kidney, thus achieving therapeutic benefit. These cases often stem from congenital insufficiency of Essence and Qi in the Kidney, termed "Zhe Yao Dou" (Broken Waist Smallpox/Chickenpox). Therefore, individuals who typically have a pale complexion, or occasionally a flushed face, prominent whites of the eyes, slow speech, frequent neck pain, a Hong-Shu (surging and rapid) pulse at the Chi position, cold feet with lumbar pain, or hot feet with thirst, all exhibit signs of Kidney deficiency and should receive preventive regulation and tonification. The waist is governed by the Kidney and serves as a major joint of the body. When Blood and Qi flow freely, there is peace; when Blood stasis and Qi stagnation occur, pain arises. When the Kidney is solid, flexion and extension are strong; when the Kidney is deficient, flexion and extension are difficult. Thus, lumbar pain is strictly contraindicated in smallpox/chickenpox cases. However, pain during the initial fever stage indicates that accumulated toxins are just beginning to move, with extreme hyperactivity of fire-heat and deficiency of Kidney Water, leading to lumbar pain. The treatment for this should involve ascending and releasing combined with nourishing Yin, cooling blood, and clearing toxins. If symptoms arise from dryness and withering, one should immediately nourish the Blood. If pain is due to severe Kidney deficiency, one should particularly double the dosage of agents that nourish Yin and tonify the Kidney. If treatment fails and symptoms worsen to include chest elevation and cold feet, it indicates Kidney failure and deep-seated toxin, which is certainly difficult to save. However, men who contract smallpox/chickenpox with lumbar pain after marriage and sexual activity can be treated, as their condition stems from acquired deficiency. In contrast, lumbar pain in boys is difficult to treat, as it stems from insufficiency of congenital Water, representing true deficiency.