Fibromyalgia, a condition characterized by excessive somatic hyperalgesia, and irritable bowel syndrome (IBS), a prevalent gastrointestinal disorder characterized by abdominal pain/discomfort and altered bowel function, often occur together. Up to 32% of patients with fibromyalgia have IBS, and 81% report irregular bowel habits.
In the April 2004 issue of Annals of the Rheumatic Diseases, Mark Pimentel, MD, and colleagues reported the results of a study that examined the association between fibromyalgia and small intestinal bacterial overgrowth (SIBO), which has been linked to IBS. The double-blind study used the lactose breath test (LBT) to examine SIBO in patients with fibromyalgia (n = 42), patients with IBS (n = 111), and controls (n = 15). The results demonstrated that 100% of the patients with fibromyalgia and 84% of those with IBS had an abnormal LBT, compared with 15% of controls. The authors concluded that an abnormal LBT (indicative of SIBO) may be a common link between fibromyalgia and IBS.