This is a multi-center, non-randomized, open label study. Subjects will be enrolled on a walk-in basis. Screening data will be reviewed to determine subject eligibility. Subjects who meet all inclusion criteria and none of the exclusion criteria will be entered into the study. All children will be exposed to non-radioactive 13C-Urea with citric acid, and shall submit a stool sample.

Centers will house a PyloPlus UBT Analyzer to document results. PyloPlus Analyzer results shall remain blinded to the investigator and treating physician. No patient management decisions should be made based on the investigational PyloPlus® UBT System.

Treating physician will prescribe a H. Pylori Stool Antigen Test to Stool test at either LabCorp or Quest Diagnostic, for the patient, which will be used for diagnostic purposes by the ordering physician.

Total duration of study is anticipated to be approximately 6 months.

Inclusion Criteria:

• Male or female age 3-17 at the time of visit
• Subject/Legal guardian (and subject when relevant) is willing to sing the Informed Consent/Assent Form
• Naive to H. pylori treatment in the past 4 weeks

Exclusion Criteria:

• Pregnant and/or lactating women
• Presence of a condition or abnormality that in the opinion of the Investigator would compromise the safety of the patient of the quality of data
• Participation in other interventional trials
• Allergy to test substrates
• Antibiotics taken within 4 weeks of the testing
• Study subjects shall not consume the following items at least 1 hour prior to the PPUBT test: Mouthwash, Chewing Gum, Carbonated Beverages, Cigarette Smoke, Acetone (to simulate the effect of ketone production that may result from some diets), Alcohol, Food
• Children 12 years and older - to be excluded after a written notification from the sponsor is received at the site that the limit of (approx.) 1/3 of the sample size was achieved for this group