The goal of this observational study is to learn how common Helicobacter pylori (H. pylori) infection is in adults without stomach or upper gastrointestinal symptoms who are having a preventive screening colonoscopy. Endoscopic screening of the stomach is yet not acceptet as a standard screening procedure in Western countries. However, Helicobacter pylori infection is known to increase the risk of developing gastric cancer. This study will look at the prevalence of Helicobacter pylori infection in asymptomatic patients who have an additional gastroscopy during the same session as their screening colonoscopy. It will also record other early tissue changes or risk factors for stomach cancer, such as intestinal metaplasia and Barrett's mucosa. The main questions this study aims to answer are: * How often is Helicobacter pylori found in adults without upper gastrointestinal symptoms by use of OGD? * Are there any correlations between H. pylori infection and other risk factors, such as BMI, smoking, alcohol consumption, or a family history of colorectal and/or stomach cancer? About 1000 participants are expected to take part. Adults undergoing a screening colonoscopy at a private endoscopy center will be offered the chance to have an additional gastroscopy if they meet the study's inclusion criteria (no previous Helicobacter pylori infection and no upper gastrointestinal symptoms). Small tissue samples (biopsies) will be taken from the stomach and lower esophagus during the gastroscopy. Biopsies will be checked histologically for the presence of Helicobacter pylori and early tissue changes. During the gastroscopy, no additional procedures or biopsies will be done beyond what is normally performed during a routine examination. Everything done during this procedure follows the standard steps of a regular gastroscopy. All data will be coded to protect participant privacy. Researchers will use statistical methods to find out how common Helicobacter pylori infection is and whether it is related to other lifestyle or family risk factors or tissue changes.