To assess the efficacy of esomeprazole 40 mg once daily in subjects who still had heartburn after receiving rabeprazole

Inclusion Criteria

• - Male or female aged 20 years or more
• - Documented history of reflux esophagitis verified by endoscopy in the past, including the grade of Los Angeles (LA) classification (Lundell LR et al 1999) before treatment
• - Ongoing (until date of Visit 1) treatment with rabeprazole 20 mg, given once daily, for a period of 4 to 8 weeks. The subject must take Rabeprazole at least 4 days a week in the past 7 days prior to Visit 1.
• - Persisting symptoms of heartburn during the past 7 days prior to Visit 1, judged by the investigator(s) as follows: At least 2 days with moderate (i.e. discomfort sufficient to cause interference with normal activities) to severe symptoms (i.e. incapacitating, with inability to perform normal activities) OR At least 4 days with symptoms including mild ones (i.e. awareness of sign or symptom, but easily tolerated).
• - The subject needs to be able to understand and read the official languages of the country.