Inclusion Criteria:  Adult patients with gastric mucosal lesions (erosion, bleeding, redness, and edema) in acute gastritis or acute exacerbation of chronic gastritis. Patients prescribed with Mucosta®SR Tab. according to the medical considerations of the investigator. Patients who have given a written informed consent to participation of this PMS and use of personal information after execution of the contract with the surveillance study site.  Exclusion Criteria:  Patients with prior history of prescription with Mucosta®SR Tab. Patients with hypersensitivity to Rebamipide or its component ingredients. Patients deemed not suitable for surveillance enrollment according to investigator's medical judgment