A Phase I/III Study of D961H 10 mg and 20 mg in Japanese Paediatric Patients With Gastrointestinal Acid Related Diseases

Inclusion Criteria: * Provision of signed written informed consent from the patient's guardian * Patients aged ≥ 1 year to 14 years old * Patients who have a diagnosis of or suspected to have GU, DU, AU, NERD, RE or Zollinger-Ellison syndrome. Exclusion Criteria: * Patients less than 10 kg in weight. * Use of any other investigational compounds or participations in another clinical trial within 4 weeks prior to the randomisation/registration. * Significant clinical illness within 4 weeks prior to the registration * Presence of hepatic diseases or other conditions that could interfere with evaluation of the study as judged by the investigators. * Positive for pregnancy test by urinary or lactation for post-menarchal females. * Previous total gastrectomy