Population selection, inclusion and exclusion criteria: All of the participants with functional dyspepsia will be tested for Helicobacter Pylori (HP) using the stool antigen test. After this phase we will have to groups of patients, dyspeptic HP (+) and dyspeptic HP (-). The first group will be the intervention group and the dyspeptic HP (-) patients will serve as control group. None the patients or the endoscopist will know which group each patient belongs.