Far more than a simple digestive organ, the gut contains an extensive neural network and immune system, earning it the title of the second brain. In modern settings, irritable bowel syndrome, or IBS, represents a state where this intestinal sensitivity is heightened. Clinical medicine points to FODMAPs as a significant driver of IBS symptoms. FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, which are carbohydrates that are poorly absorbed in the small intestine and travel to the large intestine, where they are rapidly fermented by gut microbiota. As these sugars undergo fermentation in the large intestine, they produce excess gas and draw water into the bowel, causing abdominal distension, abdominal pain, diarrhea, and constipation. Common items such as garlic, onions, legumes, certain grains like wheat and barley, dairy, fruits like apples and pears, and even vegetables like mushrooms and broccoli can carry high amounts of FODMAPs.
The concepts of hypofunction of the spleen and stomach, food stagnation, and dampness-phlegm from the Donguibogam align closely with modern understandings of the gut-brain axis and gut dysbiosis. When chronic stress or irregular meals disrupt the gut-brain axis, intestinal motility can accelerate or slow down abnormally, producing hypersensitivity. In addition, an imbalance between beneficial bacteria and harmful bacteria prompts hypersensitivity reactions to specific foods. High-FODMAP foods feed the gut microbiota, driving excess fermentation; the resulting gas and metabolic byproducts irritate the intestinal barrier and can provoke mild inflammatory responses. These changes stimulate intestinal nerve endings, sending distress signals back to the brain and perpetuating a cycle of discomfort. Rather than being isolated stomach pain, it reflects how the brain processes heightened signals from the gut. For this reason, moderating high-FODMAP foods serves as a practical dietary step for managing IBS.
