 Determination of H. pylori status Prior to enrollment, the status of H. pylori infection will be determined by 1 rapid urease test CLO test, Kimberly-Clark, USA from antrum biopsy, 2 histological examination Giemsa stain of antral and body samples two from the antral mucosa and two from the corpus mucosa, and 3 culture. Positive in any two of the three tests will be defined as positive for H. pylori infection. After-treatment H. pylori status will be determined by 13C-Urea Breath Test 13C-UBT at 6 weeks after the completion of treatment. Successful eradication of H. pylori is defined as a negative 13C-UBT result. 