Helicobacter Rescue Therapy With High-dose Esomeprazole and Amoxicillin Dual Therapy Versus Bismuth-containing Quadruple Therapy

This study aims at evaluating efficacy and safety of high-dose esomeprazole and amoxicillin dual therapy(esomeprazole and amoxicillin) versus bismuth-containing quadruple Therapy(bismuth，esomeprazole，tetracycline and furazolidone) in H. pylori rescue therapy. It is hypothesized that high-dose esomeprazole and amoxicillin dual therapy is non-inferior to bismuth-containing quadruple Therapy. Patients with confirmed failure of H. pylori eradication will be randomized to one of the treatments described above. At week 6 follow-up visits, a urea breath test，rapid urease test or helicobacter pylori stool antigen test will be performed to confirm eradication.