Rumination syndrome is included in the field of functional disordersFunctional disorder, but not malignant diseases in gastroenterology. However, unfortunately, recognition of rumination syndrome may not be prevalent. In addition, its pathophysiology remains unclear, and its therapeutic strategy is not established. From the above situation, despite being a benign disease, it markedly impairs patients’ quality of life and social functioning. Therefore, according to the diagnostic criteria, differential and definitive diagnosis of rumination syndrome from other similar diseases, such as gastroesophageal reflux disease, belching disorders, and nausea and vomiting disorders, is very important for appropriate treatment, such as cognitive-behavioral therapy. Indeed, stress is involved in the pathophysiology of rumination syndrome. However, daily stress cannot be avoided in general populations, especially for patients with this disease. Therefore, building doctor–patient relationships must be crucial for alleviating patients’ stressful, poor condition and improving their condition.