Mandatory medical device diagnostics.
- Gastroduodenoscopy (endoscopy of the stomach and duodenum) with biopsies (tissue sampling)
- From the age of 50 years, gastritis classification should be performed by endoscopy AND histology (two biopsies (tissue samples) each from the antrum (area in front of the gastric outlet) and corpus (body of the stomach)) as part of an initial diagnosis.