Improvement of Functional Dyspepsia After Drinking Alkaline Ionized Water From Alkaline Ionizer

Inclusion Criteria: * Symptoms onset should start at least 6 months before diagnosis based on one or more of the following symptoms Rome IV criteria (Unpleasant postprandial fullness, early satiety, epigastric pain, epigastric burning sensation) * No evidence of structural disease in gastroscopy within the last 3 months * Aged 19-70 years * Who meets Rome IV criteria for functional dyspepsia * Who have 4 or more symptoms based on the gastrointestinal symptom rating scale * Patients who voluntarily agree to participate in this study and sign a written consent Exclusion Criteria: * Subjects who have a history of serious malignancy including gastrointestinal malignancy, cerebrovascular disease, and heart disease within the past 6 months were excluded * Subjects who have uncontrolled diabetes and hypertension despite appropriate management * Subjects who have a history of peptic ulcer or reflux esophagitis within the past 6 months were excluded * Subject who have history of gastrointestinal surgery were excluded * Women who are pregnant or breastfeeding * Subjects who are taking drugs that may affect the gastrointestinal tract (minimum of 2 weeks washout period is necessary before participating in the trial (Medications include H2 receptor blockers, anticholinergics, prostaglandins, proton pump inhibitors, gastromucosal protection agents, corticosteroids, non-steroidal anti-inflammatory drugs, aspirin, mucosal protective agents, etc.) * Subjects who are under drugs for therapeutic purposes such as functional food that promotes gastric health * Subjects who consumed more than 14 times alcohol per week in case of man and 7 times per week in case of female in the past 1 month