Heat- and Humidity-Related Digestive Disorders: How Acupuncture Can Help

When heat and humidity disrupt digestion

Every Québec summer, when the mercury climbs and the air turns heavy with humidity, a familiar parade of digestive complaints resurfaces:

• Bloating and gas
• Slow digestion, heaviness and post-meal drowsiness
• Loss of appetite or nausea
• Acid reflux and heartburn
• Loose, sticky stools, even summer diarrhea (or, conversely, constipation in some people).

These discomforts, often dismissed as trivial, overlap substantially with what Western medicine calls functional dyspepsia (upper-stomach discomfort, early satiety, with no detectable organic lesion) and irritable bowel syndrome (IBS). These disorders significantly impair quality of life. In Traditional Chinese Medicine (TCM), many of these manifestations stem from a single mechanism: an excess of Heat-Dampness lodged in the digestive sphere.

⚠️ Important note: This post is not intended to replace medical advice. Certain warning signs call for prompt medical evaluation (see our recommendations at the end of the article). Acupuncture then fits in as a complementary and safe approach.

The TCM paradigm: Heat-Dampness (湿热) of the Spleen and Stomach

In TCM, the Spleen and Stomach (the Middle Burner, or Zhong Jiao) govern the transformation and transport of food and fluids. When this system is weakened or overloaded, fluids stagnate and form Dampness (Shi).

Combined with a Heat factor (Re) — whether climatic (heavy summer weather) or dietary (fatty, sugary meals, alcohol) — Dampness "cooks" and transforms into the Heat-Dampness syndrome (湿热, Shi-Re).

This syndrome settles primarily at the level of the stomach and spleen. Contemporary scientific literature, for that matter, links this clinical profile to disorders of gastrointestinal motility.

Typical signs to watch for

• At the gastric level: Heaviness, reflux, heartburn, nausea, a pasty or bitter mouth, heavy breath.
• At the intestinal level: Loose, sticky or foul-smelling stools, to be distinguished from "Cold-Dampness" diarrhea.
• The central sign: A yellow, greasy tongue coating on examination of the tongue.

💡 Did you know? These age-old categories now have measurable correlates. Recent work links the Heat-Dampness constitution to a specific gut-microbiota signature and connects the yellow, greasy tongue coating to an imbalance of the bacterial flora.

The summer paradox: when cold food sustains Dampness

To fight the heat, the summer reflex is to reach for the icy: raw vegetables galore, ice-cold drinks, ice cream or smoothies straight from the freezer.

Yet in TCM, the stomach needs a relative source of warmth to carry out its function as the "digestive cauldron." A constant influx of icy foods forces the organ to draw on its reserves to warm up before it can digest.

Direct consequence: The process slows down, promoting stagnation, fermentation, bloating and the well-known post-meal energy slump.

The trap: Over time, cold food depletes the Yang of the Spleen (the energy of transformation). In trying to cool down, we sustain internal Dampness, which merges with the ambient Heat.

The evidence: what the research says

How do these treatments hold up under clinical trials? Let's look at the facts transparently.

1. Functional dyspepsia: solid evidence

This is where the data are most convincing. A randomized clinical trial published in the Annals of Internal Medicine showed that acupuncture significantly improves the response rate and the resolution of cardinal symptoms (post-meal heaviness, early satiety) compared with a sham-acupuncture group (placebo). Recent meta-analyses confirm a clear improvement in quality of life with no increase in adverse effects.

2. Nausea and reflux: the indispensable PC6 (Neiguan) point

Located on the inner forearm, the Neiguan point (PC6) is one of the most studied in the world. Consolidated data from the Cochrane database show that stimulating it with needles or acupressure significantly reduces the likelihood of nausea and vomiting. This antiemetic mechanism transfers effectively to nausea of summer digestive origin.

3. Irritable bowel syndrome (IBS): encouraging results

For IBS, the picture is broadly positive but more heterogeneous. A recent systematic review (14 trials, more than 2,000 patients) shows that acupuncture significantly improves the quality of life of patients with IBS compared with conventional treatments. For diarrhea-predominant IBS (IBS-D), a large randomized trial found that electroacupuncture achieves efficacy comparable to that of loperamide (a reference antidiarrheal) on stool frequency — a notable result for a drug-free approach. A recent meta-analysis further confirms a benefit of acupuncture for IBS-D accompanied by anxiety and depression, illustrating its action on the gut-brain axis.

How acupuncture works: the physiological mechanisms

Medical research now explains the action of the needles through three main pathways:

• Gastrointestinal motility: Stimulating the Zusanli point (ST36), below the knee, modulates gastric peristalsis through vagovagal reflexes via the vagus nerve. Electroacupuncture helps normalize gastric emptying by acting on the smooth muscle, regulating both sluggish digestion and accelerated transit.
• The anti-inflammatory effect: Acupuncture activates the cholinergic anti-inflammatory pathway, thereby protecting the intestinal epithelial barrier. This is a key point for calming the fire of "Heat-Dampness."
• Microbiota regulation: By calming the autonomic (sympathetic) nervous system, acupuncture helps restore an environment favorable to the balance of the intestinal flora.

Treatment in practice at Clinique Shanti

At Clinique Shanti, every treatment plan is individualized. We identify the dominant imbalance (the share of Heat, of Dampness, or an underlying Yang deficiency) through the interview, pulse assessment and examination of the tongue.

Frequently selected points

• ST36 (Zusanli): Harmonizes the stomach, supports the Spleen, regulates transit.
• PC6 (Neiguan): Calms reflux, nausea and gastric anxiety.
• CV12 (Zhongwan) & ST25 (Tianshu): Major local points to disperse bloating and regulate the intestines.
• SP9 (Yinlingquan) & SP6 (Sanyinjiao): Specific points to drain Dampness and metabolize fluids.
• LI11 (Quchi): Used to clear systemic Heat.

💡 The clinical nuance: In a context of pure Heat-Dampness, the use of moxibustion (heat) is contraindicated or highly targeted. You don't warm a picture that is already hot! This is where the practitioner's experience makes all the difference.

Lifestyle tips to dry Heat-Dampness

To get the most out of your acupuncture sessions, here are a few simple adjustments:

• Moderate raw and icy foods: Favor cooked or lukewarm foods (light soups, steamed vegetables), easier for the gastric "cauldron" to assimilate.
• Add a warm element: drinking a lukewarm herbal tea (such as peppermint, fennel or cardamom) at the end of a meal supports the stomach without diluting the gastric juices.
• Don't drown your digestion: Drink between meals rather than large amounts of iced water while you eat.
• Lighten your plate in heavy weather: Cut back on fried foods, dense dairy, refined sugar and alcohol, which are major generators of internal Dampness.

🚨 When should you see a doctor without delay?

Some digestive symptoms should not be chalked up to the rigors of summer. See a doctor promptly if you have:

• Unexplained weight loss
• Blood in the stool or black stools
• Persistent vomiting or fever
• Difficulty swallowing or intense, sudden abdominal pain
• Any major, new digestive disturbance appearing after age 50.

Acupuncture always fits alongside appropriate medical follow-up, never in its place.

Book an appointment

Would you like to prepare your digestive system to face the summer heat?

👉 Book an appointment at our Montréal clinic (Rosemont)

👉 Book an appointment at our Magog clinic

Scientific references

• Gender differences in Damp-Heat Syndrome: A review. Biomedicine & Pharmacotherapy, 2021.
• Damp-heat constitution influences gut microbiota and urine metabolism. Heliyon, 2022.
• TCM treatment of diarrhea by regulating intestinal microbiota. Frontiers in Pharmacology, 2024.
• Yang J.-W. et al. Effect of Acupuncture for Postprandial Distress Syndrome: A Randomized Clinical Trial. Annals of Internal Medicine, 2020;172(12):777-785.
• Efficacy and safety of acupuncture for functional dyspepsia: a systematic review of RCTs.
• Zhou J. et al. The effect of acupuncture on quality of life in patients with irritable bowel syndrome: a systematic review and meta-analysis. PLOS One, 2025;20(2):e0314678.
• Zheng H. et al. Electroacupuncture for patients with diarrhea-predominant IBS or functional diarrhea: a randomized controlled trial. Medicine (Baltimore), 2016;95(24):e3884.
• Lee A., Fan L.T. Stimulation of the wrist acupuncture point PC6 for preventing postoperative nausea and vomiting. Cochrane Database of Systematic Reviews.
• The effectiveness of acupuncture in prevention and treatment of postoperative nausea and vomiting: a systematic review. PLOS One, 2013.
• Electroacupuncture at ST36 modulates gastric motility via vagovagal and sympathetic reflexes. World Journal of Gastroenterology, 2019.
• Yang Q. et al. Effect of electroacupuncture at Zusanli (ST36) on gastric motility: PKC and MAPK signalling. BMC Complementary and Alternative Medicine, 2014.
• Hu S. et al. Electroacupuncture at Zusanli (ST36) prevents intestinal barrier dysfunction through the cholinergic anti-inflammatory pathway. Evidence-Based Complementary and Alternative Medicine, 2013.
• Electroacupuncture at ST36 ameliorates gastric dysmotility via the nucleus tractus solitarius–vagal axis. World Journal of Gastroenterology.
• Wang Z. et al. Efficacy of acupuncture for diarrhea-predominant IBS with comorbid anxiety and depression: a meta-analysis. Medicine (Baltimore), 2024;103(46):e40207.