Persistent fatigue despite adequate food intake points beyond a local digestive issue to systemic nutritional imbalance and metabolic disorder. In modern medicine, this can be understood within the spectrum of malabsorption syndrome. The spleen and stomach function described in the Donguibogam aligns closely with digestive system function, particularly the nutrient absorption capacity of the small intestine and large intestine, the activity of digestive enzyme-secreting organs such as the liver and pancreas, and the regulatory interactions of the nervous system and endocrine system.
After food undergoes initial digestion in the stomach, the small intestine absorbs primary macronutrients such as carbohydrates, protein, and fat, alongside micronutrients such as vitamins and minerals. The villus and microvillus structures of the small intestinal mucosa maximize surface area to support efficient absorption. However, when disruptions affect this process, food is neither properly broken down nor effectively transferred across the intestinal barrier into the bloodstream. As a result, the body lacks adequate calories and nutrients, leading to systemic symptoms such as chronic fatigue, lethargy, weight loss, reduced muscle mass, and decreased immunity.
The clinical causes of malabsorption are varied. First is digestive enzyme deficiency. When pancreatic dysfunction, such as pancreatitis or cystic fibrosis, impairs the secretion of enzymes needed to break down carbohydrates, protein, and fat, digestion itself is compromised. Second is bile acid deficiency. Bile acid, produced in the liver and stored in the gallbladder, is necessary for fat digestion and absorption; biliary tract obstruction or decreased liver function can impair fat uptake. Third is small intestinal mucosa damage. Inflammatory bowel disease, such as celiac disease with gluten intolerance, Crohn's disease, and ulcerative colitis, damages the small intestinal mucosa and reduces nutrient absorption. In addition, dysbiosis, such as small intestinal bacterial overgrowth, parasitic infection, and medications like antibiotics or antacids, can compromise mucosal integrity and induce malabsorption. Fourth, reduced gastric acid secretion from gastric surgery or atrophic gastritis impairs the absorption of key nutrients, particularly vitamin B12.
The gut-brain axis is especially significant in this context. Rather than acting as a passive absorption tube, the digestive system possesses its own enteric nervous system and communicates continuously with the brain. Psychological factors such as stress, anxiety, and depression directly affect intestinal motility, digestive enzyme secretion, and intestinal permeability seen in leaky gut syndrome, potentially hindering nutrient absorption. Conversely, gut dysbiosis affects the production of neurotransmitters like serotonin and dopamine, influencing mood and cognitive health. Chronic malabsorption can reduce cognitive function and induce nervous system fatigue, reinforcing a cycle of lethargy and depression.
If persistent fatigue continues regardless of food intake, it should not be dismissed as simple exhaustion. Consulting a gastroenterology specialist for a thorough evaluation and taking structured steps to restore gut health are critical, as chronic malabsorption serves as a systemic indicator of overall health.
