Breath tests are used to diagnose many conditions. SIBO is just one of them. Others include:
Lactose intolerance
Fructose intolerance
H. pylori
The SIBO breath test is the industry gold standard. That means that most experts agree it’s the best way to test for SIBO.
A doctor can also test for SIBO using something called an aspirate, where they take a sample of fluid from your small intestine. This is expensive and often inaccurate though, so it’s rarely used.