This study aims at evaluating efficacy and safety of Saccharomyces boulardii combined with bismuth-containing quadruple Therapy versus bismuth-containing quadruple Therapy(bismuth#esomeprazole#tetracycline and furazolidone) in H. pylori rescue therapy. It is hypothesized that Saccharomyces boulardii combined with bismuth-containing quadruple Therapy is superior 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.

The study will include three phases: screening, treatment and follow-up. Screening: this phase will last a maximum of 14 days and subjects eligibility will be evaluated after signing informed consent. One of urea breath test#rapid urease test or helicobacter pylori stool antigen test will be performed in addition to the baseline routine evaluations.

Treatment: Subjects are randomly assigned to treatment and will be treated for 14 days. A randomization visit will take place on Day 0 and an end-of-treatment visit will take place between day 14 and 16.

Follow-up: includes one visits. Approximately 28 days after the end of treatment. Eradication of H. Pylori will be confirmed by one of urea breath test#rapid urease test or helicobacter pylori stool antigen test.

Inclusion Criteria:

• Age between 18~75, both gender.
• Patients who had failed H.pylori eradication therapies .
• Women are eligible if they are not pregnant or nursing, and if they are of childbearing potential they are required to use medically acceptable contraception for the duration of the study and 30 days thereafter.

Exclusion Criteria:

• Patients who have previously used tetracycline and furazolidone antibiotics to eradicate infection with H. pylori.
• Contraindications to study drugs.
• Substantial organ impairment, severe or unstable cardiopulmonary or endocrine disease.
• Constant use of anti-ulcer drugs ( including taking proton-pump.inhibitors(PPI) within 2 weeks before the [13C] urea breath test), antibiotics or bismuth complexes (more than 3 times /1 month before screening).
• Pregnant or lactating women.
• Underwent upper gastrointestinal Surgery.
• Dysphagia.
• Evidence of bleeding or iron efficiency anemia.
• A history of malignancy.
• Drug or alcohol abuse history in the past 1 year.
• Systemic use of corticosteroids, non steroidal anti-inflammatory drugs, anticoagulants, platelet aggregation inhibitors (except the use of aspirin for less than 100 mg/d).
• Mental disorder.
• Enrolled in other clinical trials in the past 3 months.
• Refuse to sign informed consent.