Question: How to diagnose Autoimmune atrophic gastritis ?
Answer: How is autoimmune atrophic gastritis diagnosed? A diagnosis of autoimmune atrophic gastritis is generally not suspected until characteristic signs and symptoms are present. Additional testing can then be ordered to confirm the diagnosis. This generally includes: A biopsy of the affected tissue obtained through endoscopy Blood work that demonstrates autoantibodies against certain cells of the stomach
Source: GARD

Question: What are the treatments for Autoimmune atrophic gastritis ?
Answer: How might autoimmune atrophic gastritis be treated? The treatment of autoimmune atrophic gastritis is generally focused on preventing and/or alleviating signs and symptoms of the condition. For example, management is focused on preventing vitamin B12, folate and iron deficiencies in the early stages of the condition. With adequate supplementation of these vitamins and minerals, anemia and other health problems may be avoided. If pernicious anemia is already present at the time of diagnosis, replacement of vitamin B12 is generally recommended via injections. In some cases, endoscopic surveillance may also be recommended due to the increased risk of certain types of cancer. While surgery may be appropriate for the treatment of related cancers, we are not aware of surgical management options or recommendations otherwise. Symptoms of gastritis in general may be managed with prescription or over-the-counter medications (besides antibiotics for H. pylori-associated gastritis) that block or reduce acid production and promote healing. Proton pump inhibitors reduce acid by blocking the action of the parts of cells that produce acid. Examples may include omeprazole, lansoprazole, rabeprazole, esomeprazole, dexlansoprazole and pantoprazole. Histamine (H-2) blockers reduce the amount of acid released into the digestive tract, which relieves gastritis pain and promotes healing. Examples include ranitidine, famotidine, cimetidine and nizatidine. Antacids that neutralize stomach acid and provide pain relief may also be used. We are not aware of dietary guidelines or recommendations for autoimmune atrophic gastritis. Much of the literature on dietary management of gastritis is specific to H. Pylori-associated gastritis. However, people with gastritis in general may find some relief by eating smaller, more-frequent meals; avoiding irritating foods; avoiding alcohol; switching pain relievers; and managing stress.
Source: GARD