What are reliable tests for diagnosing stomach cancer? Knowing h pylori is common,  how can I get tested for it?

Upper Endoscopy. The gold standard test for diagnosing stomach cancer is upper endoscopy. In countries where stomach cancer is more common, such as japan, the entire population is screened for this cancer, much like what we recommend for colon ca. H pylori testing (the bacteria responsible for ulcer disease) can be done directly during upper endoscopy or through blood tests (or a breath test).
Endoscopy. Upper endoscopy for diagnosis. If h pylori +, get treatment with triple therapy (2 antibiotics/1 acid reducer). To check that you cleared infection there is a stool test. Talk to your doctor.

Related Questions

How long can you have symptomatic h.pylori before it turns into stomach cancer?

Why do you ask? The large majority of folks with this infection never get cancer from it. It's moot. If you are symptomatic, get treated. If someone has told you not to do this, they are wrong. Use "natural healing" (there are a bunch of claims) only as an adjunct. Best wishes. Read more...