Hydrogen breath test

A hydrogen breath test (or HBT) is used as a diagnostic tool for people with irritable bowel syndrome, and common food intolerances. The test is simple, non-invasive, and is performed after a short period of fasting (typically 8–12 hours). Even though the test is normally known as a "Hydrogen Breath Test" some physicians may also test for methane in addition to hydrogen. Many studies have shown that some patients (approximately 35% or more) do not produce hydrogen but actually produce methane. Some patients produce a combination of the two gases. Other patients, who are known as "Non-Responders", don't produce any gas; it has not yet been determined whether they may actually produce another gas. In addition to hydrogen and methane, some facilities also utilize carbon dioxide (CO₂) in the patients' breath to determine if the breath samples that are being analyzed are not contaminated (either with room air or bronchial dead space air).