Constantly Running to the Bathroom? Five Hidden Causes of Chronic Diarrhea

Chronic diarrhea is too complex a condition to dismiss as merely having a sensitive gut. Modern medicine approaches chronic diarrhea from multiple perspectives, categorizing it broadly into malabsorption, inflammatory conditions, and functional disorders. One common cause is diarrhea-predominant irritable bowel syndrome. When communication along the brain-gut axis is disrupted, intestinal motility can become abnormally rapid and sensitivity to pain increases. Psychological factors such as stress and anxiety directly alter intestinal motility, frequently triggering diarrhea. This corresponds closely to the observation in the Donguibogam that liver qi stagnation impairs digestive function. Other notable causes include small intestinal bacterial overgrowth and gut dysbiosis. The small intestine normally contains relatively few bacteria. When bacteria proliferate excessively, they produce gas and toxins during the breakdown of food, leading to diarrhea and abdominal pain. This parallels the description in the Donguibogam of the non-transformation of water and grain, where food is not processed properly. When the spleen weakens and digestion and absorption slow, an environment develops where microorganisms can easily induce excessive fermentation. Malabsorption of specific food components is also common. Lactose intolerance occurs from a deficiency in lactase, the enzyme that breaks down lactose in dairy products, while fructose intolerance stems from an impaired ability to absorb fructose. In addition, gluten sensitivity, whether celiac disease or non-celiac gluten sensitivity, bile acid malabsorption, and pancreatic enzyme deficiencies can all cause chronic diarrhea and malabsorption. Within the broader framework of Korean medicine, these correspond to spleen-stomach deficiency, where the body cannot properly transform and convey food. Chronic diarrhea interferes with the absorption of essential nutrients, which can lead to secondary problems such as anemia, vitamin deficiencies, weight loss, and chronic fatigue. Because gut health is directly connected to immunity, persistent diarrhea warrants professional evaluation to identify the precise cause.