Patients who require gastric endoscopy, including the patient population* excluded from the phase III controlled clinical study of NPO-11, will receive an intragastric single dose of NPO-11 20 mL. The efficacy of NPO-11 as a premedication for endoscopy will be evaluated based on the percentage of patients having no gastric peristalsis at both 2 minutes post-dose and the end of endoscopy (primary outcome measure).

The safety of NPO-11 will be evaluated based on adverse events and adverse drug reactions (ADRs) observed between administration and seven days after administration.

Patient population excluded from the phase III controlled clinical study of NPO-11

• Patients with reflux esophagitis
• Patients with active gastric or duodenal ulcers
• Patients who undergo endoscopy under sedation
• Patients who undergo endoscopy with a scope of <9 mm in diameter

Inclusion Criteria:

Inpatients or outpatients of either sex who meet criteria (1) and (2) below will be enrolled in the study. Patients have to provide written informed consent for voluntary participation in the study.

1. Patients who require gastric endoscopy (except for emergency endoscopy or endoscopy for comprehensive medical examination)
2. Patients who are older than 20 years at the time of consent

Exclusion Criteria:

Patients who meet any of the following criteria will be excluded from the study. The criteria (2) and (3) will be confirmed during endoscopy. Patients who meet any of these criteria will be withdrawn from the study at the time of confirmation.

1. Patients with a history of surgery to the stomach
2. Patients with severe gastric stenosis or deformation which makes observation of gastric peristalsis difficult
3. Patients with upper gastrointestinal bleeding which requires hemostasis
4. Patients on cancer treatment (chemotherapy or radiotherapy)
5. Patients with a history of shock or hypersensitivity to l-menthol or peppermint oil (mint oil)
6. Patients with a history of shock or hypersensitivity to lidocaine hydrochloride
7. Pregnant or lactating women, women of childbearing potential, or women who plan to become pregnant during the study
8. Patients who have been exposed to NPO-11
9. Patients who have received other investigational drugs within four months before consent or who are participating in other clinical studies
10. Patients otherwise ineligible for participation in the study in the investigator's or subinvestigator's opinion