The carbon 14 test, which costs about$100. Most clinical carbon 14 breath tests, which check the stomach for H. pylori, mainly check the level of H. pylori activity, not necessarily the amount of H. pylori. Even if the amount of H. pylori is relatively small, if it is active, most breath tests for H. pylori are strongly positive and require anti-H. pylori medication. If the amount of H. pylori is low and the level of activity is relatively small, the carbon 14 breath test may be weakly positive or mildly positive, and anti-H. pylori medication is not needed in this case. The carbon 14 breath test is radioactive, so for adults it takes 48-72 hours to metabolize, and it is not recommended to check the correlation carbon 14 test for infants, children, etc.