Since Helicobacter pylori is a type of bacterium, it cannot be seen with the naked eye. However, current research indicates that Helicobacter pylori is strongly associated with certain mucosal appearances under endoscopy. Therefore, endoscopists can infer the presence of an infection based on certain mucosal appearances observed during the procedure.

However, if the only purpose is to test for Helicobacter pylori infection without needing a gastroscopy, then we can opt for non-invasive methods such as the carbon-13 urea breath test, carbon-14 urea breath test, stool antigen test, and serological antibody tests, which are commonly used methods of testing. Moreover, after treatment for Helicobacter pylori, it is recommended to use either the carbon-13 or carbon-14 urea breath test for examination.