Robert Shmerling, M.D., is associate physician and clinical chief of rheumatology at Beth Israel Deaconess Medical Center and an associate professor in medicine at Harvard Medical School. He is an active teacher in the Internal Medicine Residency Program, serving as the Robinson Firm Chief. He is also a teacher in the Rheumatology Fellowship Program and has been a practicing rheumatologist for over 25 years.
Is there a connection between IBS and fibromyalgia?
While there is no definite, direct connection between them, irritable bowel syndrome (IBS) and fibromyalgia do occur together in many people.
Fibromyalgia is a painful condition of the bones, muscles and joints associated with poor quality sleep, fatigue and multiple areas of soreness. It is also diagnosed by its symptoms. Tests of the joints, muscles and bones are normal.
The cause of both conditions is unknown.
Several studies have noted an increase of fibromyalgia among people with IBS and an increase of IBS among people with fibromyalgia. The meaning of this is unclear. They could have a similar (or even identical) cause, but whether the trigger that starts them is something in the environment, a genetic tendency or a combination of the two is unknown.
The treatment of fibromyalgia could make the symptoms of IBS worse. For example, amitriptyline (Elavil), a drug often prescribed for fibromyalgia, may make the constipation of IBS worse. And Lotronex (alosetron), prescribed for IBS, may occasionally cause muscle aches and fatigue, symptoms that are prominent with fibromyalgia.
While it's possible that IBS and fibromyalgia are more closely related than is currently recognized, we need a better understanding of these conditions to know how the observation that they occur together may shed light into cause, prevention and treatment.