The best test for SIBO today is combined hydrogen methane breath testing using glucose as a substrate. Its effectiveness is proven in multiple studies in well established journals. It is able to detect SIBO in both hydrogen and methane producers, and is very accurate.
It is simple and usually conducted in a clinic setting.
This test has become available in Singapore in the past 3-4 years. It is available in the some of the tertiary hospitals in the public sector, including SGH, NUH, TTSH and CGH. In the private sector, this test is available in gutCARE, our digestive group practice. The reference link provides more information about the test and how to arrange for one.
Sincerely
Dr Jarrod