Infection with bacteria, primarily Helicobacter pylori.
Certain diseases, such as pernicious anaemia, chronic bile reflux, stress and certain
autoimmune disorders can cause gastritis as well.
The most common symptom is abdominal upset or pain. Other symptoms are indigestion,
abdominal bloating, nausea, and vomiting. Some may have a feeling of fullness or
burning in the upper abdomen.