Patients with dyspepsia will have negative impact to their life and common cause is Helicobactor pylori infection. Rapid urease test is the easy available and rapid method to test the infection but the test may be interfered by proton pump inhibitor, bismuth or antibiotics .In general, patients with dyspepsia usually take proton pump inhibitor to relieve dyspepsia so those patients may not stop the drug before test the infection with rapid urease test. So author aims to measure the sensitivity of rapid urease test from biopsy of body, which H. pylori would migrate if the patients still take proton pump inhibitor and biopsy of antrum, which is standard location of biopsy compare to pathology for H. pylori in each sites in patients who do not stop taking proton pump inhibitor

The investigators contacted patients who had an appointment for esophagoendoscopy(EGD) at Chulalongkorn Hospital to inform and review patient's history. If patients matched inclusion and did not meet exclusion criteria, the participants would tell the information of the study including proposal, method, risk and benefit then the investigators asked for consent to participate in the study.

If patients decided to participate then the investigator corrected the information in CRF form which was sex, age, underlying disease, smoking history, alcohol drinking history, current and past medication especially PPI and NSIADs, EGD and rapid urease test history, H. pylori treatment history, duration of taking PPI drug.

EGD was done by endoscopist with standard method. The investigator performed biopsy at antrum, 5 cm proximal to pylorus lesser curvature, and body, greater curvature opposite to angularis by standard forceps. The biopsy would take 2 times from each site for rapid urease test and histopathology test for H. pylori. The endoscopists change forceps after finishing biopsy in each site to reduce contamination. The EGD finding was recorded After the investigators test H. pylori by rapid urease test, the result was read at 24 hours at room temperature. The color changing from yellow to pink was positive test, which mean there was H. pylori infection. In contrast, negative test was no color changing.

For Histopathologic test, the investigators fixed sample in formalin, infiltrated the tissue with paraffin then embedded. Stained with Hematoxylin & Eosin and looked for H. pylori by 2 histopathologists, who were blinded the result to each other and result of rapid urease test. If negative study, the histopathologists would stain tissue with giemsa and corrected data again. All gastric tissue will be sent for immunohistochemistry as a gold standard for this study.

Inclusion Criteria:

• Patients with dyspepsia and have indication for esophagogastroscopy
• Patients who take PPI at least 2 weeks and stop the drug less than 2 weeks
• Age above 18 years old

Exclusion Criteria:

• Patients who diagnosed to have iron deficiency anemia and have signs of previously bleeding gastric ulcer
• Active upper gastrointestinal bleeding or recent bleeding
• previous gastric surgery
• patients who take bismuth or antibiotic in last 4 weeks
• Coagulopathy, INR>1.5, Platelet < 100,000
• gastric cancer
• Life expectancy less than 3 months
• Deny to participate in the study

The pathologists will be blinded for the result of endoscopic finding and rapid urease test.