Clinical Characteristics of Small Intestinal Bacterial Overgrowth in Individuals with Abdominal Distention

Inclusion Criteria: 1. Patients aged 18 to 70 years. 2. Patients presenting with the primary complaint of abdominal bloating and/or abdominal distension, or those exhibiting abdominal distension with prominence over other symptoms. Exclusion Criteria: 1. Patients who are pregnant or lactating. 2. Patients have history of gastrointestinal malignancy or gastrointestinal surgery. 3. Patients manifesting food intolerance or presenting with a confirmed diagnosis or suspicion of lactose intolerance. 4. Patients with urinary system (chronic kidney disease, etc.), immune system (scleroderma, etc.), nervous system (Parkinson's disease, etc.), mental system (depression, etc.), or other diseases outside the digestive system. 5. Patients who used antibiotics or microecological agents or underwent endoscopic examination within two weeks. 6. Patients with a medication history encompassing motility enhancers, secretory enhancers, antifoaming agents, spasmolytics, opioids, and antidepressants within the past week. 7. Patients who are unwilling or incapable to provide informed consents.