Question 1

How is SIBO diagnosed?

Accepted Answer

The current gold standard for clinical diagnosis is a breath test — either lactulose or glucose. The patient drinks a fermentable sugar solution and exhaled breath samples are collected every 15–20 minutes for three hours. A rise in hydrogen of 20 ppm or more within 90 minutes, or any methane reading of 10 ppm or higher, is considered positive under the North American Consensus.

Question 2

How do I prepare for a SIBO breath test?

Accepted Answer

Follow a bland, low-fermentable diet for 24 hours before the test (plain rice, chicken, eggs, clear broth). Fast for 12 hours before the test. Pause probiotics for at least two weeks, and antibiotics for at least four weeks prior. Do not smoke or exercise vigorously the morning of the test.

Question 3

Is a breath test accurate?

Accepted Answer

Breath testing has a sensitivity of roughly 60–70% and specificity of 80–85% for detecting SIBO. It is not perfect, but it is the most accessible and evidence-based test available. Small-bowel aspirate culture is more accurate but invasive and rarely performed outside research settings.

Diagnosis

The tests

Preparation

Interpretation

Questions about diagnosis.

Knowledge is the first step to healing.