This is a multi-center, non-randomized, open label study. Subjects will be enrolled if they are deemed eligible given the inclusion criteria. Subjects who meet all inclusion criteria and none of the exclusion criteria will be entered into the study. Subjects will be exposed to non-radioactive 13C-Urea with citric acid, and may submit a stool sample or undergo endoscopy for Rapid Urease Test and Histology samples.

Center(s) 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 either prescribe a H. pylori Stool Antigen Test through P4 Diagnostics, along with another Urea Breath Test using Breath ID, or patient will undergo Endoscopy to provide a composite reference method consisting of Rapid Urease Test and Histology. These will act as the comparators to the PyloPlus Urea Breath Test System.

Inclusion Criteria:

• Male or Female at least 18 years of age
• Patients who have been diagnosed with H. pylori and have been treated within the past 6 months
• Naive to H. pylori treatment in the past 4 weeks (including PPIs)

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 or the quality of the 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