The Efficacy and Safety Study of Rikkunshito in Patients With Functional Dyspepsia

Inclusion Criteria: * -Patients diagnosed with FD according to the ROME III criteria i) Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to obtaining informed consent ii) Have not received upper endoscopy within the last 6 months prior to enrollment and do not have evidence of structural/organic disease iii) Must have one or more of the following symptoms: 1. Bothersome postprandial fullness 2. Early satiation 3. Epigastric pain 4. Epigastric burning * At least one of the FD-related symptoms on the Global Overall Symptom (GOS) scale (bothersome postprandial fullness, early satiation, epigastric pain, epigastric burning) is ≥4, whereas heartburn is ≤3. * Total score of depression-related symptoms on Hospital Anxiety and Depression Score (HAD) is ≤10. * Type of visit: Outpatient * Provides voluntary informed consent after receiving adequate explanation and demonstrates thorough understanding of the nature of the study. Exclusion Criteria: * Confirmed ulcer (excluding scars) or malignant tumor in the upper GI * Suspected organic lesions in the hepato-biliary-pancreatic regions such as cholelithiasis, hepatitis, pancreatitis * History of upper GI resection * Serious complications (liver, kidney, heart, or blood disease or metabolic disease) * Less than a year since testing positive for H. pylori or have undergone a successful eradication therapy * Use of prohibited medications * Neuropsychiatric disorders * Use of or planned use of any investigational drugs * Unable to take drugs orally * History of allergic reactions to Kampo medicines * Pregnant or lactating women or those who are planning to conceive during the study period * Deemed ineligible by principal investigator or sub-investigator