Efficacy of Esketamine for Patients With Irritable Bowel Syndrome

To explore the efficacy of a single low dose of esketamine for patients with irritable bowel syndrome (IBS).

Inclusion Criteria: 1. Age of 18 - 60 years; 2. American Society of Anesthesiologists (ASA) physical status of I - II; 3. Body Mass Index (BMI) of 15 - 30; 4. Scheduled for colonoscopy; 5. Positive screening results according to the Rome IV diagnostic criteria for IBS; 6. Patients who met Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for Anxiety disorder (ANXD) and/or major depressive disorder (MDD) . Exclusion Criteria: 1. GastrointestinalTract (GI) bleeding; 2. Any organic lesions confirmed by clinical examination, laboratory examination or colonoscopy； 3. A previous diagnosis of colon cancer, infammatory bowel disease or coeliac disease; 4. A history of weight loss (at least 10%) within six months; 5. A history of abdominal surgery (other than hernia repair or appendectomy); 6. Participate in other clinical trials within 3 months; 7. Patients older than 55 years of age who have not undergone a colonoscopy in the past 5 years； 8. Mental disorder patients with severe personality disorder, active suicidal ideation and history of self-harm within 1 year; 9. Allergy or any contraindications to the drugs used in the study, such as severe cardiovascular disease, refractory hypertension, or hyperthyroidism; 10. Drinking more than 50 units (1 unit refers to 10ml of pure alcohol) per week; 11. Pregnancy or breastfeeding.