When pathogenic factors enter the interior and contend with healthy qi, abdominal pain occurs. Therefore, the causes of pain vary. Abdominal pain belongs to interior syndromes; in Taiyang channel diseases, the abdomen does not hurt. Shaoyang diseases present with chest and hypochondriac pain but no abdominal pain. If Yangming disease presents with abdominal fullness and urgent pain, this is an interior excess syndrome suitable for purgation, using Da Chai Hu Tang (Major Bupleurum Decoction) or Xiao Cheng Qi Tang (Minor Order the Qi Decoction). In the Three Yin diseases, if there is diarrhea with undigested food and abdominal pain, it is due to interior cold. The general discussion on the Yang-within-Yin of the Taiyang channel suggests using Si Ni Tang (Frigid Extremities Decoction) or Fu Zi Li Zhong Tang (Aconite Regulate the Middle Decoction). When yang qi transmits to the Taiyin channel, presenting with abdominal fullness and pain, there are two types of syndromes: excess pain and deficiency pain. Pain accompanied by borborygmus and diarrhea is deficiency pain; this section specifically discusses the Yin-within-Yang of the Taiyin channel, suggesting Xiao Jian Zhong Tang (Minor Construct the Middle Decoction), which is Guizhi Jia Shaoyao Tang (Cinnamon Twig Decoction plus Peony Root) with variations in Cinnamomi Ramulus (Guizhi, 桂枝) potency. If ineffective, use Xiao Chai Hu Tang (Minor Bupleurum Decoction) removing Huang Qin (Scutellariae Radix, 黄芩) and adding Shaoyao (Paeoniae Radix, 芍药) as per the original dosage. If abdominal fullness, constipation, and tenderness upon pressure occur, it is excess pain, treated with Guizhi Jia Dahuang Tang (Cinnamon Twig Decoction plus Rhubarb) adding one qian of Dahuang (Rhei Radix et Rhizoma, 大黄). Here, "deficiency" refers to the gradual dissipation of yang pathogenic factors, while "excess" refers to vigorous yang qi.

In Taiyang Shanghan (Cold Damage), with a choppy yang pulse and wiry yin pulse, urgent abdominal pain should be expected. First administer Xiao Jian Zhong Tang; if ineffective, administer Xiao Chai Hu Tang. (Cheng Wuji notes: A choppy yang pulse and wiry yin pulse with urgent abdominal pain indicate interior deficiency-cold, treat with Xiao Jian Zhong Tang to warm the middle and dispel cold. If ineffective, it is not interior cold but rather pathogenic factors moving from exterior to interior causing interior qi stagnation; use Xiao Chai Hu Tang removing Huang Qin and adding Shaoyao to clear the transmitted pathogen.)

Formula for Xiao Jian Zhong Tang:
Guizhi (Cinnamomi Ramulus, 桂枝) [remove bark], Shengjiang (Zingiberis Rhizoma Recens, 生姜) [sliced, each 3 liang], Shaoyao (Paeoniae Radix, 芍药) [6 liang], Gancao (Glycyrrhizae Radix et Rhizoma, 甘草) [roasted, 2 liang], Dazao (Jujubae Fructus, 大枣) [12 pieces, split], Jiaoyi (Malt Sugar, 胶饴) [1 sheng].
Boil the above six ingredients in seven sheng of water to obtain three sheng, remove dregs, add Jiaoyi, and simmer gently until dissolved. Take one sheng warm, three times daily. It cannot be used for vomiting because sweetness promotes vomiting. (The Neijing states: Liver generates on the left, Lung stores on the right, Heart is positioned above, Kidney is situated below, Spleen is Earth, corresponds to the Center, resides among the four zang organs, serves as the Central State, nourishes Ying and Wei, and circulates Jin-Ye. If disordered, Ying and Wei lose their nourishment, and Jin-Ye loses its circulation. This decoction warms and strengthens the Middle Jiao, hence named "Jian Zhong". The Spleen desires relaxation; sweet foods relax urgency. To tonify the Spleen, sweet substances are primary. Thus, Jiaoyi (sweet and warm) is the Sovereign herb, Gancao (sweet and neutral) is the Minister. Guizhi is acrid and hot, acrid disperses and moistens; when Ying and Wei are deficient, acrid-moistening disperses them. Shaoyao is slightly cold and sour-astringent, draining and collecting; when Jin-Ye is insufficient, sour-astringency guides it. Thus, Shaoyao and Guizhi are Assistant herbs. Shengjiang is acrid and warm, Dazao is sweet and warm. The Stomach is the source of Wei Qi, the Spleen is the root of Ying Qi. The Zhenjing states: Ying emerges from the Middle Jiao, Wei emerges from the Upper Jiao. Wei is Yang; deficiency requires tonification with acrid substances. Ying is Yin; deficiency requires tonification with sweet substances. Acrid and sweet combine to strengthen the Spleen and Stomach and unblock Ying and Wei; thus, Jiang and Zao are Envoy herbs. Some ask: Guizhi Tang releases the exterior with less Shaoyao, while Xiao Jian Zhong Tang warms the interior with more Shaoyao. Why? Skin is superficial, so the dose is small; Heart and Abdomen are deep, so the dose is large. This is the difference.)

In Shanghan, with heat in the chest and pathogenic factors in the stomach, abdominal pain, and desire to vomit, the main treatment is Huang Lian Tang (Coptis Decoction). (Cheng Wuji notes: After purging a dampness patient, a tongue coating resembling a胎 (fetus/membrane) appears due to heat in the Lower Jiao and cold in the Upper Chest, indicating pathogenic factors entering the interior causing lower-heat and upper-cold. This Shanghan case involves transmission to the interior causing lower-cold and upper-heat. Pathogenic factors in the stomach prevent Yin-Yang interaction. Yin fails to ascend and dominates below, causing lower-cold and abdominal pain. Yang fails to descend and dominates above, causing chest heat and desire to vomit. Administer Huang Lian Tang to regulate the ascending and descending of Yin and Yang qi.)

Formula for Huang Lian Tang:
Huanglian (Coptidis Rhizoma, 黄连), Gancao (Glycyrrhizae Radix et Rhizoma, 甘草) [roasted], Ganjiang (Zingiberis Rhizoma, 干姜) [pounded], Guizhi (Cinnamomi Ramulus, 桂枝) [remove bark, each 3 liang], Renshen (Ginseng Radix, 人参) [2 liang], Banxia (Pinelliae Rhizoma, 半夏) [half sheng, washed], Dazao (Jujubae Fructus, 大枣) [12 pieces, split].
Boil the above seven ingredients in one dou of water to obtain six sheng, remove dregs. Take one sheng warm, three times daily and twice at night. (Upper heat is drained by bitterness; Huanglian's bitterness descends Yang. Lower cold is dispersed by acridity; the acridity of Guizhi, Ganjiang, and Banxia ascends Yin. The Spleen desires relaxation; sweet foods relax urgency. Renshen, Gancao, and Dazao are sweet to tonify the Stomach.)

After five or six days of Shanghan or Zhongfeng, with alternating chills and fever, bitter fullness in the chest and hypochondrium, silence, loss of appetite, irritability, and frequent vomiting, or alternatively chest irritability without vomiting, thirst, abdominal pain, hypochondriac stiffness, epigastric palpitations, dysuria, absence of thirst with slight body heat, or cough, administer Xiao Chai Hu Tang.
Two-Yang concurrent disease: At the onset of Taiyang disease, incomplete sweating leads to transmission to Yangming, with continued mild sweating and no aversion to cold. If Taiyang symptoms persist, do not purge; induce mild sweating instead. If the face is persistently red, Yang qi is constrained in the exterior; resolve it with fumigation. If sweating was incomplete, causing restlessness, unknown pain location (sometimes abdominal, sometimes limb), unpressable pain, shortness of breath, it is due to incomplete sweating; re-sweat to cure, known by the choppy pulse. (Guizhi Tang for non-aversion to cold, Da Chai Hu Tang for mild sweating, Ge Gen Tang or Gui Zhi Ma Huang Ge Ban Tang, Ma Huang Jia Gui Zhi Tang.)

Yangming disease: Patients who have not had a bowel movement for five or six days, with periumbilical pain, restlessness occurring at specific times, have dry feces causing constipation. (Cheng Wuji notes: No bowel movement for five or six days implies dry feces. Dryness and excess in the Stomach prevent Qi descent, causing periumbilical pain and timed restlessness.) After severe purgation, if there is no bowel movement for six or seven days, unresolved restfulness, and abdominal fullness, there are dry feces. This is because old food remains; Da Cheng Qi Tang (Major Order the Qi Decoction) is indicated. (After severe purgation, the Stomach is weak and cannot digest food. By day six or seven, old food condenses and does not digest, causing unresolved restlessness and abdominal fullness/pain, indicating dry feces. Use Da Cheng Qi Tang to purge them.) If sweating fails to resolve the condition and abdominal fullness/pain occurs, urgently purge.

Shaoyin disease: If not improving after two or three days, and by four or five days presents with abdominal pain, dysuria, heavy/painful limbs, and spontaneous diarrhea, this is Water Qi retention. Symptoms may include cough, vomiting, diarrhea, or patent urination. Treat with Zhen Wu Tang (True Warrior Decoction). (Cheng Wuji notes: By day two or three, pathogenic factors are shallow; by day four or five, they are deep. Kidney governs Water; Kidney disease fails to control Water, leading to fluid retention and Water Qi. Abdominal pain indicates severe interior cold-dampness. Heavy/painful limbs indicate severe exterior cold-dampness. Dysuria and diarrhea indicate dampness excess causing failure to separate clear and turbid. Neijing states: Dampness excess causes loose stools. Use Zhen Yu Tang to tonify Yang and scatter cold-dampness.) In Shaoyin disease, with diarrhea of undigested food, interior cold with exterior heat, cold extremities, faint/almost imperceptible pulse, yet no aversion to cold and red complexion, or alternatively abdominal pain, dry retching, sore throat, or cessation of diarrhea with absent pulse, treat with Tong Mai Si Ni Tang (Pulse-Regulating Frigid Extremities Decoction). (Diarrhea of undigested food, cold extremities, faint pulse indicate interior cold. Fever, no aversion to cold, red face indicate exterior heat. This is Yin excess internally repelling Yang externally, lacking communication. Use Tong Mai Si Ni Tang to scatter Yin and unblock Yang.) In Shaoyin disease with cold extremencies, optionally cough, palpitations, dysuria, abdominal pain, or heaviness in defecation, treat with Si Ni San (Frigid Extremities Powder). (Si Ni refers to cold extremities. In Three Yang diseases, hands/feet are hot; in Taiyin, they warm themselves; in Shaoyin, heat pathogens deepen, causing cold extremities. In Jueyin, cold extremities are worse than Si Ni. Use Si Ni San to scatter transmitted heat.) In Shaoyin disease progressing from two/three days to four/five days, with abdominal pain, dysuria, persistent diarrhea with pus/blood, use Tao Hua Tang (Peach Blossom Decoction). (By day four/five, cold pathogens penetrate deeply. Abdominal pain is interior cold. Dysuria is failure to separate clear/turbid. Persistent diarrhea with pus/blood is weak intestines/stomach and insecure Lower Jiao. Use Tao Hua Tang to secure intestines and stop diarrhea.)

Taiyin disease: Presents with abdominal fullness, vomiting, inability to eat, worsening spontaneous diarrhea, and intermittent spontaneous abdominal pain. Purging will cause hardness below the chest. (Alternatively use Li Zhong Tang/Wan; if no thirst, use Si Ni Tang etc.). Originally a Taiyang disease, mistaken purging caused abdominal fullness and intermittent pain, belonging to Taiyin. Use Guizhi Jia Shaoyao Tang; for severe excess pain, use Guizhi Jia Dahuang Tang (see previous).

Jueyin disease: After four or five days of Shanghan, if abdominal pain occurs with gas moving downward toward the lower abdomen, diarrhea is impending. (Day four/five is when pathogens transmit to the interior. Abdominal pain with gas moving down indicates interior deficiency meeting cold, cold Qi descending, impending spontaneous diarrhea. Alternatively use Fu Zi Gan Jiang Tang or Si Ni Tang.)

Yun states: Pathogens in the Three Yin fail to communicate internally, causing abdominal pain. Hand-Foot channels converge in the abdomen. If pulse is wiry with abdominal pain, the issue is Foot Jueyin Liver and Hand Taiyin Lung; puncture Taichong (LR3), Taiyuan (LU9), Tailing (PC7). If pulse is deep with abdominal pain, the issue is Foot Taiyin Spleen, Shaoyin Kidney, and Hand Jueyin Pericardium; puncture Taixi (KI3), Tailing (PC7). If pulse is deep-thin with pain, the issue is Foot Taiyin Spleen and Hand Shaoyin Heart; puncture Taibai (SP3), Shenmen (HT7), Sanyinjiao (SP6). This is the method for acupuncture in abdominal pain.

Wu states: Abdominal pain that can be pressed/rubbed indicates interior deficiency; pain that cannot be pressed/rubbed indicates interior excess. Wang Haicang says: Pain in Zhongwan (CV12) belongs to Spleen Earth. With deep-thin pulse and interior cold, use Li Zhong Tang or Fu Zi Li Zhong Wan. If Yang pulse is choppy and Yin pulse is wiry, use Xiao Jian Zhong Tang. Small abdominal pain belongs to Jueyin channel; use Dang Gui Si Ni Tang plus Wuzhuyu. Cold extremities: Si Ni Tang plus Wuzhuyu. Severe excess with abdominal fullness/pain, periumbilical stabbing pain, constipation, and solid pulse: purge with Da Cheng Qi Tang. Tidal fever, constipation, hardness/fullness/pain from epigastrium to lower abdomen, intolerant to touch: purge with Da Xian Xiong Tang. Wiry pulse, abdominal pain, no heat/cold: use Shaoyao Gancao Tang. Wiry pulse, bitter taste, fever, abdominal pain: use Xiao Chai Hu Tang removing Renshen, adding fried Baishao. Alternating chills/fever with abdominal pain: add Rougui (Cinnamomi Cortex, 肉桂) and Shaoyao. Excess cold with pain: remove Huang Qin, double Rougui and Shaoyao. Shaoyin fever with cold extremities and abdominal pain: Si Ni San plus Fuzi, Tang Rougui, fried Shaoyao, Wuzhuyu. Fever with surging-wiry pulse and abdominal pain: Shaoyao Huangqin Tang. Generally, abdominal pain has deficiency/excess and cold/heat; differentiate by pulse/symptoms. Blood stasis also causes abdominal pain, intolerant to touch (see specific section). Spontaneous diarrhea with abdominal pain and clear urine requires warming; use Li Zhong or Si Ni based on severity. Mild cases: Wu Ji San; severe: Si Ni Tang; pulseless: Tong Mai Si Ni Tang to retreat Yin and restore Yang. Abdominal pain with desire to vomit/diarrhea and restlessness often involves Sha Du (sand poison); worldly practice scrapes/stabs Weizhong (BL40). Wiry-micro pulse with small abdominal pain (Jueyin): puncture Taichong, Taiyuan, Tailing; moxa Guilai (ST29), Guanyuan (CV4). Deep pulse with umbilical pain (Shaoyin): puncture Taibai, Shenmen, Sanyinjiao; moxa Zhongwan (CV12).

Tao states: In Shanghan, if drinking cold water relieves abdominal pain slightly, it is heat; use cooling herbs. If ineffective, with hard periumbilical pain, solid stool, irritability/thirst, it is dry feces pain; urgently purge with cold herbs. Food stagnation pain is treated similarly. Hard lower abdominal pain, patent urination, black stool, yellow eyes/body: blood stasis pain; treat similarly, add blood-invigorating herbs, pass black matter to heal. These three follow the principle of pain relief through discharge. If drinking water worsens pain, it is cold; use warming herbs. If ineffective, with cold extremities, abdominal pain, vomiting, diarrhea, urgently use hot herbs; verify pulse strength first. Liu uses ash packs to moxa abdominal pain. Pang states: Failure to moxa when indicated leads to cold congealing and Qi rushing to the heart, causing death.

Huo states: No high fever, irritability/thirst, solid stool, or abdominal fullness/rash: regulate Stomach with Tiao Wei Cheng Qi Tang or Huanglian Jupi Tang.

Abdominal pain combined with headache, fever, body ache, vomiting/diarrhea is Huoluan ( Cholera ). Desire to vomit but cannot, desire to defecate but cannot is Gan Huoluan (Dry Cholera); see Miscellaneous Diseases Huoluan section.