1. To compare 10-day sequential therapy and 14-day modified bismuth quadruple therapy and to establish more effective first-line regimen for the eradication of Helicobacter pylori in Korea.
2. To evaluate the effect of H. pylori eradication therapy on the symptom improvement of functional dyspepsia

Emerging evidence shows that the eradication rate of proton pump inhibitor (PPI)-based triple therapy for the first-line treatment of Helicobacter pylori has decreased. The reason for the decrease in the efficacy of PPI-based triple therapy is mainly due to the increase in the resistance against clarithromycin. Sequential therapy seems to be more effective than the PPI-based triple therapy, however, the eradication rate of sequential therapy in Korea, which is mostly under 80%, is still not satisfactory. Modified bismuth quadruple therapy which replace metronidazole with amoxicillin (contained PPI, bismuth, tetracycline and amoxicillin) can be a promising regimen because the antibiotic resistance rate of tetracycline and amoxicillin are relatively low in Korea and amoxicillin is more easy to take in comparing with metronidazole. Therefore, the aim of this study is to compare 10-day sequential therapy and 14-day modified bismuth quadruple therapy and to establish more effective first-line regimen for the eradication of Helicobacter pylori in Korea.

In addition, previous studies reported that H. pylori infection also associated with functional dyspepsia (FD) and recommended H. pylori eradication in patients with FD. However, until now, there was no randomized prospective study in Korea, therefore the another aim of this study is to evaluate the effect of H. pylori eradication therapy on the symptom improvement of FD.

Inclusion Criteria:

• Male and female Korean Adult (Aged ≥ 18 years)

• Patients who diagnosis of H. pylori infection by any of following three methods

  • positive rapid urease test (CLOtest)
  • histologic evidence of H. pylori by modified Giemsa staining
  • positive 13C-urea breath test

Exclusion Criteria:

• Age under 18 years
• Previous eradication treatment for H. pylori
• Patients who took any drug which could influence the study results such as proton pump inhibitor, H2 blocker, mucosal protective agent and antibiotics
• History of gastrectomy
• Advanced gastric cancer or other malignancy
• Abnormal liver function or liver cirrhosis
• Abnormal renal function or chronic kidney disease
• Other severe concurrent diseases
• Previous allergic reactions to the study drugs
• Pregnant or lactating women