To diagnose indigestion, your doctor will ask about your symptoms, examine you and may also ask about your medical history. If lifestyle changes and medicines don't help, your doctor may recommend other tests, eg breath tests or blood tests to detect the presence of H. pylori; gastroscopy-a procedure used to look inside your oesophagus, stomach and your duodenum. During a gastroscopy your doctor may take a biopsy(small sample of tissue) to be tested. The doctor may also request a barium swallow and meal X-ray-a test where you swallow a drink containing barium(which shows up on X-ray images).X-ray images then show the inside of your bowel more clearly.
Attribution: BUPA