Digestive diseases caused by obesity and their differentiation in traditional Chinese medicine.

Cholecystitis, cholelithiasis, and fatty liver: Obesity, digestive and liver dysfunction, high-energy diets, fatty foods, and lipid metabolism disorders lead to excessive cholesterol reaching saturation, resulting in gallstones, primarily cholesterol stones. The incidence is twice that of individuals with normal weight. Cholelithiasis can cause biliary colic, and secondary infections can lead to acute or chronic cholecystitis. 68%–94% of obese individuals have fatty degeneration in their livers, with over half (25%–35%) of hepatocytes showing fatty infiltration. The concentrations of fatty acids and triglycerides in the livers of obese individuals are higher than in those with normal weight.

Infections: Obese individuals have reduced resistance to infection, making them more susceptible to respiratory infections. The incidence of pneumonia is higher. Skin folds are prone to abrasion, leading to dermatitis; boils, urinary tract infections, and digestive system infections are also more common. There are reports of appendicitis occurring at twice the rate of normal weight. In cases of acute infection, severe trauma, surgery, and anesthesia, obese individuals have poor stress responses, often resulting in more severe conditions, lower tolerance for surgery and anesthesia, slower postoperative recovery, and increased complications and mortality. Furthermore, obese individuals have slower physical reactions, making them more vulnerable to various injuries, accidents such as car crashes, and fractures, and more serious limb injuries.

Some patients may experience psychological distress. Weight gain before and during pregnancy can affect the labor process and its consequences. Reports indicate that heavier mothers are more likely to develop preeclampsia and diabetes than lighter mothers, require more cesarean sections, have longer labors, and have heavier average birth weights. Differential diagnosis is crucial. Traditional Chinese medicine has recorded obesity as early as two thousand years ago, with the earliest mention in the *Neijing* (Inner Canon of Medicine), such as in the *Lingshu* (Spiritual Pivot), Chapter on Disorders of Wei Qi: "The Yellow Emperor asked: How can one determine whether someone is fat or thin? Qi Bo replied: People can be fat, greasy, or fleshy... Those with firm and full flesh are fat; those with loose flesh and loose skin are greasy; those with skin and flesh not separated are fleshy."

Obese patients are classified into three basic types: "fat," "fat-like," and "muscular." The *Ling Shu* (Spiritual Pivot), in its chapter on "Reversal and Order of Fat and Lean," describes the characteristics of obesity as "broad shoulders and armpits, thin flesh and thick, dark skin, lips that are almost touching, blood that is black and turbid, and qi that is sluggish and slow." The causes of obesity vary, and the manifestations also differ. Based on symptoms, it can be divided into several syndrome types. 1. Spleen and Stomach Heat Accumulation Type. [Symptoms] Commonly seen in adolescents, with a robust and obese physique, ruddy complexion, high spirits, increased appetite, excessive hunger, dry mouth and bitter taste, constipation, yellow urine, prone to internal heat, mouth ulcers, halitosis, strong body odor, occasional abdominal distension or burning pain in the stomach, red tongue with a yellow and greasy coating, and a wiry, slippery, and forceful pulse.

[Analysis] Adolescents are in the growth and development stage and need to consume more nutrients. As a result, their spleen and stomach functions are vigorous, hence they have an increased appetite and are prone to hunger. Their qi and blood production is sufficient to nourish their bodies, often resulting in a plump and robust physique, rosy complexion, and full of energy. However, if they eat too frequently, their digestion will be insufficient, and food will remain in the stomach, causing abdominal distension. Over time, this can generate heat, leading to burning pain in the stomach. Depletion of body fluids and qi, which cannot ascend, can cause dry mouth, bitter taste, mouth sores, and bad breath. If the large and small intestines are not properly nourished, constipation and yellow urine will occur. A red tongue with a yellow and greasy coating and a wiry, slippery, and forceful pulse are all signs of accumulated heat in the spleen and stomach.

2. Spleen Deficiency and Poor Transportation Type. [Symptoms]Obesity and bloating, fatigue, heaviness in the body, drowsiness, normal or reduced appetite, often with a history of overeating, mild edema in the limbs (worse in the evening and milder in the morning, aggravated by exertion), difficulty urinating, loose stools or constipation, pale and swollen tongue with teeth marks on the edges, thin white or greasy white coating, and a weak and thready pulse. [Analysis]This patient has a weak spleen constitution or has previously damaged the spleen and stomach qi through overeating, hence the common reduced appetite. The spleen and stomach are the source of qi and blood production; spleen deficiency leads to insufficient qi and blood production, resulting in insufficient blood to nourish the spirit, causing fatigue, heaviness in the body, and drowsiness. Insufficient qi fails to propel fluid circulation, leading to obesity, bloating, difficulty urinating, and mild edema in the limbs.

Yang energy rises in the morning and is stored away in the evening, hence edema is milder in the morning and more severe in the evening. Exhaustion after exertion depletes energy and also worsens edema. Spleen qi deficiency impairs the transformation and transportation of fluids, leading to loose stools when fluids flow down to the large intestine. Alternatively, spleen and stomach qi deficiency can cause constipation as food stagnates in the intestines for too long. A pale, swollen tongue with teeth marks on the edges, a thin white or greasy white coating, and a weak, thready pulse are signs of spleen deficiency. 3. Phlegm-Dampness Accumulation Type. [Symptoms]Commonly seen in middle-aged women, characterized by obesity, a soft, thick abdomen, weak and sagging muscles, heavy limbs, lethargy, facial swelling, chest tightness, excessive phlegm, fatigue, drowsiness, dizziness, reduced thirst, excessive phlegm in the throat, and excessive vaginal discharge.

Irregular bowel movements, a large, pale tongue with teeth marks, a white, greasy or slippery tongue coating, and a weak, slow pulse. [Analysis] Congenital phlegm-dampness constitution or excessive consumption of rich, fatty foods leads to excess fat accumulation. Long-term obesity can affect the spleen and stomach's digestive function, damaging the spleen qi, resulting in a bloated physique, fatigue, preference for lying down, chest tightness, shortness of breath, abdominal distension, a pale, large tongue with teeth marks, a white, greasy or slippery tongue coating, and a weak, slow pulse. 4. Qi stagnation and blood stasis type. [Symptoms] More common in women, with an obese physique, purplish-red or dark red complexion, chest tightness and rib distension, frequent headaches, chest pain, rib pain, irregular menstruation, irritability, insomnia or restless sleep, increased appetite, and constipation.

The tongue is dark and purplish-red, or has ecchymosis or petechiae, with sublingual veins, and the pulse is choppy or deep and wiry. [Analysis] Liver dysfunction leads to stagnation of Qi, affecting the spleen and stomach's function of transporting and transforming food and fluids, as well as bile excretion. This impairs the transportation and transformation of food, resulting in obesity, fullness and discomfort in the chest and hypochondrium, abdominal distension, hiccups, irregular menstruation in women, insomnia, and excessive dreaming. The tongue is dark and purplish-red, or has ecchymosis or petechiae, with sublingual veins, and the pulse is choppy or deep and wiry. 5. Spleen and Kidney Yang Deficiency Type. [Symptoms] Obesity, weak and flaccid muscles, pale complexion, puffy face, lethargy, shortness of breath, spontaneous sweating, and worsening of shortness of breath with exertion; aversion to cold, lower back and knee pain, and lower limb edema.

Frequent urination with clear urine, less urine during the day and more urine at night, loose stools, thin and clear vaginal discharge, lack of libido, swollen and tender tongue with a moist white coating, and a deep and slow pulse. [Analysis] Spleen qi deficiency prevents the transformation of dampness, leading to subcutaneous fat accumulation; kidney yang deficiency prevents the transformation of qi and the movement of water, thus hindering urination and causing internal retention of dampness, exacerbating obesity. Common symptoms include obesity, fatigue, lower back pain, dizziness, shortness of breath, cold limbs, lower limb edema, swollen and tender tongue with a moist white coating, and a deep and slow pulse.