Leaky gut syndrome, also known as intestinal permeability, occurs when the lining of the small intestine becomes damaged, allowing toxins, undigested food particles, and bacteria to leak into the bloodstream. This triggers chronic inflammation, digestive issues, and even autoimmune reactions. While conventional medicine is still catching up to the importance of gut health, functional medicine recognizes leaky gut as a root cause of many chronic conditions, including bloating, fatigue, skin issues, and joint pain.