Fibromyalgia has been linked to small intestinal bacterial overgrowth along with irritable bowel syndrome.

If you have fibromyalgia and also experience digestive issues, your gut problems may be more than a coincidence.

“There’s a definite correlation between gut health and fibromyalgia,” says R. Swamy Venuturupalli, MD, a rheumatologist in Beverly Hills, California, whose practice focuses on treating autoimmune and inflammatory diseases. Though researchers vary in their estimates, “there’s a higher incidence of irritable bowel syndrome (IBS) in people with fibromyalgia,” Dr. Venuturupalli says. “Some reports say approximately 60 percent of people with fibromyalgia have IBS, and conversely, 60 or 70 percent of people with IBS also have fibromyalgia.” And, he notes, a study published in March 2015 in the journal Medicine found that people with fibromyalgia were 1.5 times more likely than others to have IBS, the symptoms of which include chronic abdominal pain, constipation, diarrhea, and nausea.