When Stress Causes Stomach Pain and Diarrhea, Could the Aged Tangerine Peel in Your Kitchen Hold the Answer?

On the kitchen spice rack, there is always one or two forgotten items. That jar of aged tangerine peel—bought with enthusiasm for braising meat and brewing tea—sits there six months later with a dusty lid. But if you asked a Chinese medicine practitioner what ingredient should always be stocked at home, nine out of ten would mention it. In Chinese medicine, aged tangerine peel holds a status somewhat like salt in the kitchen—unassuming, yet indispensable. It is warm in nature, bitter and pungent in flavor, and enters the Spleen and Lung channels. It regulates qi and strengthens the Spleen, dries dampness and transforms phlegm. Today, however, we are not discussing coughs or excessive phlegm. Instead, we will trace the intricate connections between this humble ingredient and the pattern of "stomach pain and diarrhea whenever stressed."

Interestingly, modern medicine classifies this condition as a subtype of irritable bowel syndrome (IBS), with gastrointestinal motility disorders, visceral hypersensitivity, and brain–gut axis dysregulation as popular explanations. Yet more than two thousand years ago, Chinese medicine had already approached this matter from an entirely different path. Its entry point was not the intestines, but the subtle relationship between the Liver and the Spleen.

I. The Liver–Spleen Conflict: How Emotions Stir the Gut

In the Huangdi Neijing: Suwen, Chapter 5, "The Great Treatise on the Correspondence of Yin and Yang," there is a passage that remains thought-provoking today:

"Anger harms the Liver; pensiveness harms the Spleen... Anger makes qi rise, joy makes qi slow, grief makes qi dissipate, fear makes qi descend, cold contracts qi, heat causes qi to leak, shock disorders qi, overexertion depletes qi, and pensiveness binds qi."

"Pensiveness binds qi"—where does this binding occur? Possibly in the chest and hypochondrium, possibly in the epigastrium and abdomen. The Spleen governs transportation and transformation; it thrives on free flow and dislikes stagnation. When a person is chronically overthinking and mentally tense, qi movement tends to become blocked at the central pivot. The Spleen and Stomach's rhythm of transformation is disrupted: what should ascend fails to ascend, what should descend fails to descend, and water and waste in the intestines cannot move smoothly. The result is abdominal distension and irregular bowel movements. This does not yet directly explain "stomach pain and diarrhea when stressed," but it has already pointed out the general direction: emotions are never merely a matter of the mind—they leave visible traces in the body.

Modern research has also found that there is a bidirectional communication pathway between the brain and the gut, known as the "brain–gut axis." During stress or anxiety, certain signaling molecules released by the brain can directly alter intestinal motility and secretory function. This resonates remarkably with the traditional Chinese medical theory that "the Liver governs free coursing and regulates qi movement." However, Chinese medicine goes one step further than modern medicine—it is not satisfied with describing the phenomenon, but asks which organ first falls out of balance.

II. Liver Qi Encroaching on the Spleen: How Stress Turns into Abdominal Pain and Diarrhea

In the Jingyue Quanshu, under the section on diarrhea, there is a passage that seems almost tailor-made for today's topic:

"Whenever one encounters anger and then has diarrhea, it must first be the case that anger was accompanied by eating, which injured the Spleen and Stomach. Thus, when anything triggers these emotions again, the condition immediately flares up. This is a disease of both the Liver and the Spleen."

Zhang Jingyue observed a pattern: some people develop diarrhea whenever they experience emotional fluctuations, and the root cause lies in "anger accompanied by eating, injuring the Spleen and Stomach"—that is, the Spleen and Stomach are already weak, and their defenses collapse under emotional impact. He summarized it with the five characters "a disease of the Liver and Spleen." In Chinese medical theory, the Liver belongs to Wood and the Spleen belongs to Earth. Wood should normally dredge Earth and assist its transportation and transformation. But if Liver qi becomes depressed or hyperactive, it instead "encroaches upon" Spleen Earth and disrupts its normal function. Tension, anxiety, and fear—these emotions, in the Chinese medical physiological view, all fall under the category of Liver free-coursing dysfunction.

When Liver qi is not smooth, depression transforms into wind; wind and wood stir, and the Spleen and Stomach are attacked. The result is intestinal spasm, accelerated motility, and failure to transform dampness. If one asks further, "Why do some people only get sweaty palms when nervous, while others go straight to the bathroom?" The answer lies in constitutional differences. The same surge of Liver qi, in a person with robust Spleen qi, may at most cause distension in the hypochondrium—it can withstand the force. But in a person with inherently deficient Spleen qi, it is like a flood breaching the levee, pouring straight downward. How do you know which type you are? Look at the accompanying symptoms.

III. Two Common Constitutional Foundations: The Relative Severity of Liver Depression and Spleen Deficiency

Liver Depression Predominant: Pain More Severe than Diarrhea

If stress triggers stomach pain and diarrhea, accompanied by notable abdominal distension, frequent belching, and fullness in both hypochondria; if pain lessens after defecation but distension remains; if one is prone to sighing, irritability, shallow sleep, and excessive dreaming; if the tongue body is reddish with turbid white coating on both sides, and the pulse is wiry—this may be a pattern primarily of Liver qi depression. The disease location is the Liver, the disease nature is qi stagnation, and the disease tendency is excess. Abdominal pain tends to be more prominent in this type, because the root of the pain is "chaotic movement of qi"—the qi of the intestinal organs is squeezed with no outlet.

Spleen Deficiency Predominant: Diarrhea More Severe than Pain

If stress causes less intense abdominal pain, but the urge to defecate comes suddenly and violently, with loose or watery stool; if one usually feels fatigued, has poor appetite, drowsiness after meals, and a sallow complexion; if the tongue is pale and swollen with teeth marks, and a thin white coating, and the pulse is soft and moderate—this may be a pattern primarily of Spleen qi deficiency with Liver qi encroaching upon it. The disease location is the Spleen, the disease nature is deficiency mixed with excess, and the disease tendency is slower but more lingering. People in this group often have symptoms not only under stress—even a little cold or greasy food will make the intestines "protest."

Clinically, these two types are not strictly separated. Most people present with deficiency mixed with excess, or excess mixed with deficiency, with only a difference in emphasis. If the primary and secondary aspects are confused, the treatment direction may go completely off course—warm-tonifying a predominately depressed pattern is like adding fuel to fire; while aggressively smoothing Liver qi in a predominately deficient pattern may over-move qi and worsen the diarrhea.

IV. The Sense of Proportion Between Kitchen and Medicine Cabinet

Stress-induced stomach pain and diarrhea—it can be a major issue or a minor one. It is not life-threatening, but it is enough to ruin an important exam, a critical presentation, or a carefully planned date. For this reason, many people are eager to find a "take it and it's cured" method. This feeling is completely understandable, but the wisdom of Chinese medicine lies precisely in not rushing to give an answer, but first seeing clearly the layers of the problem.

Returning to that jar of aged tangerine peel: it does regulate qi, transform dampness, and strengthen the Spleen to harmonize the Middle. Adding a few slices of aged tangerine peel to congee, soup, or hot water in daily diet can indeed help people with Spleen deficiency complicated by dampness stagnation. But if you treat aged tangerine peel as an "anti-diarrheal medicine," you will likely be disappointed—it does not astringe the intestines. It is warm and drying in nature. People with obvious Yin deficiency with internal heat or Liver depression transforming into fire may find that overuse causes dry mouth, thirst, irritability, and insomnia. Moreover, the power of a single ingredient is ultimately limited. Regulating the body is like untying a knot—you need to find where the end of the rope is.

There is also an easily overlooked point: daily rhythm. People who frequently stay up late, have irregular meals, or sit for long periods without exercise will have reduced self-repair capacity of the Spleen and Stomach, even if they are careful with their diet. Regarding emotional regulation, there is no need to force yourself to "feel better"—the more you force relaxation, the more tense you become. What you can do is reduce "secondary stress": since stress will cause diarrhea anyway, arrange bathroom time before going out to give your body time to adapt. As for exercise, gentle physical activities such as walking, Baduanjin, and Tai Chi help qi flow smoothly. However, the specific type and duration of exercise should be determined by a licensed Chinese medicine practitioner based on individual constitution—do not simply follow what others say.

V. No One-Size-Fits-All Protocols: Learn to Observe Your Own Body

After all this discussion, if you remember only one sentence, let it be this: do not blindly copy any "internet miracle anti-diarrheal remedy." The essence of Chinese medicine pattern differentiation lies in "treating the same disease with different approaches"—even when stress causes stomach pain and diarrhea in different people, Person A may need to soothe the Liver as the primary approach, Person B may need to strengthen the Spleen, and Person C may need to regulate both Liver and Kidney. The difference lies in the details. A professional Chinese medicine practitioner will make a comprehensive judgment based on tongue signs, pulse signs, constitutional characteristics, and lifestyle habits, rather than handing out a generic formula.

So, the next time stress gives you stomach pain and diarrhea, try setting aside the anxiety of "how to stop it" and instead observe three questions: Is the pain around the navel or below it? After defecation, do you feel relief or fullness? Are your hands and feet usually warm or cold, and how do your emotions fluctuate? These details are the codes your body sends to you. Interpreting them brings you closer to the starting point of solving the problem than rushing to find a method of "immediate relief."

Have you ever considered that "stomach pain and diarrhea whenever stressed" may not simply be your intestines throwing a tantrum—it might be your body's way of reminding you that the old partnership between the Liver and Spleen has not been working well for quite some time?

References:

1. The original text of the Huangdi Neijing: Suwen can be consulted in the Traditional Chinese Medicine Ancient Literature Database: https://tcmdata.cintcm.com/

2. World Health Organization strategic document on traditional medicine: https://www.who.int/health-topics/traditional-complementary-and-integrative-medicine

3. Official website of the National Administration of Traditional Chinese Medicine: https://www.satcm.gov.cn/

Related Knowledge Q&A