Helicobacter pylori(H.pylori), which infects about 50% of the global population, has been classified as the first risk factor of gastric cancer. Strong evidence supports that H.pylori eradication is an effective approach to reduce the incidence of those pathological processes. Antimicrobial susceptibility test can pick out sensitive drugs to kill H.pylori, and reduce secondary drug resistance. However, there is a lack of high quality RCT to evaluate its efficacy in the rescue treatment of Helicobacter infection.~The investigator's study aims to assess the efficacy of 14-day antimicrobial susceptibility test guided quadruple therapy for the rescue treatment of Helicobacter pylori infection. Then, comparing this regimen with 14-day empirical therapy according to personal medication history to tell which one is better in clinic practice.
The purpose of this study is to assess efficacy of 14-day antimicrobial susceptibility test guided quadruple therapy for the rescue treatment of Helicobacter pylori infection, then comparing it with 14-day empirical therapy according to personal medication history.