The bacteria called Helicobacter pylori is one cause for gastritis in the abdominal area, including the antrum that is the lower stomach region, relates Merck Manuals. This bacteria can cause an infection that can lead to gastritis or peptic ulcers. However, gastritis can also be caused by a virus or fungi.
Gastritis is a condition in which there is inflammation of the stomach lining. An H. pylori infection causes chronic inflammation of this lining, reports MedicineNet. Although some people may not experience any symptoms, other people can present symptoms of a H. pyloric infection that include pain in the abdominal area, vomiting, anemia, bloating and nausea. To diagnose this infection, blood and stool tests can be used. Treatment for gastritis involves the use of antibiotics for the infection and medications that inhibit acid production in the stomach, reports the Mayo Clinic.