Blood tests. The doctor may perform

Blood tests. The doctor may perform various blood tests such as checking your red blood cell count to determine whether you have anemia, which means that you do not have enough red blood cells. He or she can also screen for H. pyloriinfection and pernicious anemia with blood tests.
Fecal occult blood test (stool test). This test checks for the presence of blood in your stool, a possible sign of gastritis.