4. Conscious sedation is performed by non-anesthesiologist-assisted method. Intravenous midazolam 0.05-0.1 mg/kg and/or intravenous propofol 0.5mg-1mg/kg is administered. Analgesics was administered intravenous meperidine 25mg in patients with older than 50 years and meperidine 50mg in patients with younger than 50 years. To limit duodenal peristalsis hyoscine-N-butylbromide is administered intravenously.