One study that was published in Annals of the Rheumatic Diseases in 2004 found a 100% correspondence of fibromyalgia with SIBO. (4) Researchers have finally linked fibromyalgia to the health of the gut! One study showed a 100% connection between fibromyalgia and small intestine bacterial overgrowth, the direct result of an imbalanced inner ecosystem. In a double blind study, participants were asked to take a lactulose breath test, the gold standard when it comes to measuring overgrowth in the small intestine, which checks the breath for the presence of hydrogen. Bacteria produce hydrogen gas or methane as they feed. Researchers at the Cedars-Sinai Medical Center found that 100% of the participants with fibromyalgia had abnormal test results. They also found that the more abnormal the test results, the more pain a fibromyalgia volunteer was in. The degree of bacterial overgrowth in the small intestine has a direct relationship with the severity of fibromyalgia
Source: The Hidden Cause of Fibromyalgia: A Natural Remedy for Pain ‐ All Body Ecology Article