A Phase III Study of the Efficacy and Safety of Remimazolam Compared to Placebo and Midazolam in Colonoscopy Patients

Inclusion Criteria: * Male and female patients, aged ≥18, scheduled to undergo a diagnostic or therapeutic colonoscopy (therapeutic procedures could include hemostasis, resection, ablation decompression, foreign body extraction, for example). * American Society of Anesthesiologists Score 1 through 3 * Body mass index ≤40 kg/m2. * For female patients with child-bearing potential, negative result of pregnancy test (serum or urine) as well as use of birth control during the study period (from the time of consent until all specified observations were completed). * Patient voluntarily signed and dated an informed consent form that was approved by an Independent Review Board prior to the conduct of any study procedure. * Patient was willing and able to comply with study requirements and return for a Follow-up Visit on Day 4 (+3/-1 days) after the colonoscopy. Exclusion Criteria: * Patients with a known sensitivity to benzodiazepines, flumazenil, opioids, naloxone, or a medical condition such that these agents were contraindicated. * Chronic use of benzodiazepines for any indication (eg, insomnia, anxiety, spasticity). * Chronic use of opioids for any indication. * Female patients with a positive serum human chorionic gonadotropin pregnancy test at screening or baseline. * Lactating female patients. * Patients with positive drugs of abuse screen or a positive serum ethanol at baseline. * Patient with a history of drug or ethanol abuse within the past 2 years. * Patients in receipt of any investigational drug within 30 days or less than seven half-lives (whichever was longer) before screening, or scheduled to receive one during the study period. * Participation in any previous clinical trial with remimazolam. * Patients with an inability to communicate well in English with the investigator, or deemed unsuitable according to the investigator (in each case providing a reason).