I presume you mean a breath test for SIBO. It depends on what they uses as the source of carbohydrate for the SIBO test. The standard SIBO test used lactulose and looked for an early rise in hydrogen levels in the breath test. They now know that an early rise in hydrogen after ingestion of lactulose is a normal response even individuals without SIBO. In an open on-line discussion with IBS experts from UNC I asked Dr. Drossman - a member of the Rome Foundation that designed the Rome III criteria used to diagnosis IBS - what was the best test for SIBO. He said that the hydrogen breath test using glucose as the carbohydrate source was the best. Again he re-iterated that the relationship between SIBO and IBS is tenuous at best.
If you decide to have a SIBO test please tell us how it goes.
-------------------- STABLE: ♂, IBS-D 50+ years - Science of IBS