The goal of this clinical trial is to evaluate the eradication efficacy and health economic benefits of individualized regimens guided by fecal molecular susceptibility testing with 7-day and 14-day courses in the rescue treatment of Helicobacter pylori infection. The main questions it aims to answer are:

1. What is the H. pylori eradication rate of the 7-day versus 14-day individualized regimens?
2. What are the safety, adherence, and cost-effectiveness of the 7-day versus 14-day individualized regimens? Researchers will compare the 7-day course group and the 14-day course group to see if the 7-day course is non-inferior to the 14-day course in terms of eradication rate.

Participants will:

1. Undergo fecal H. pylori drug resistance gene testing
2. Receive randomized assignment to either 7-day or 14-day individualized treatment based on drug susceptibility results
3. Complete follow-up visits at 1 week and 4-8 weeks after stopping treatment for adverse event monitoring and 13C-urea breath test

Inclusion Criteria:

1. Voluntarily participate in this clinical study; fully understand, be informed about this study, and sign the Informed Consent Form (ICF).
2. Age between 18 and 75 years (inclusive) on the day of signing the ICF.
3. 13C-urea breath test (13C-UBT) and fecal HP nucleic acid detection confirming Helicobacter pylori (Hp) infection.
4. previously eradicated HP

Exclusion Criteria:

1. Individuals with a known allergy to the medication.
2. Patients with severe cardiovascular, pulmonary, renal, hepatic, hematologic, neurologic, endocrine, or psychiatric disorders;
3. Participants or guardians who refuse to enroll;
4. Alcohol and/or drug abuse (dependence or addiction) or individuals judged by the physician to have poor compliance;
5. Use of antibiotics, bismuth-containing drugs, PPIs, or traditional Chinese medicines within 4 weeks before treatment;
6. Pregnant or lactating women;
7. Any condition deemed by the investigator to be unsuitable for enrollment.