Although reflux esophagitis and irritable bowel syndrome involve dysfunction of the upper and lower gastrointestinal tracts, respectively, they share the same root cause. Autonomic nervous system imbalance, visceral hypersensitivity, and brain-gut axis disturbances cause both diseases to occur simultaneously. In fact, some studies indicate that the concomitant prevalence of these two conditions reaches 40–60%, and treating only one often leads to the other persisting or worsening. In Korean medicine, "Wei-gi-sang-yeok" (the upward movement of stomach energy) is viewed as causing reflux, while "Qi stagnation" in the intestines and "Spleen deficiency" are considered to cause Irritable Bowel Syndrome. Herbal medicines are formulated to regulate both conditions simultaneously (such as formulations that soothe epigastric tightness and heartburn, and warm the internal organs to bring down the surging energy) tailored to the patient's constitution. Acupuncture is also approached integrally by utilizing acupoints from both the upper and lower gastrointestinal tracts. For organic reflux esophagitis (erosive), it is safer to combine this treatment with conventional internal medicine medication.