Irritable Bowel, Pain Syndromes Linked

Sept. 28, 2006 -- Doctors have long suspected a link between irritable bowel syndrome, pain syndromes, and depression. New data now strongly support this theory.

The findings come from data on 97,593 people with irritable bowel syndrome enrolled in a large U.S. health plan from 1996 to 2002. J. Alexander Cole, DSc, MPH, and colleagues at Boston University compared these patients with 27,402 people seeking routine health care.

Their results show that people with irritable bowel syndrome are:

• 80% more likely to suffer fibromyalgiafibromyalgia
• 60% more likely to suffer migraine
• 40% more likely to suffer depression
• Overall, 60% more likely to suffer fibromyalgia, migraine, or depression

"Perhaps what is driving the relation between irritable bowel syndrome and these other conditions is some underlying biological disorder," Cole tells WebMD. "Nobody is sure what this could be. But people suggest that there is this constellation of symptoms among people with irritable bowel syndrome, fibromyalgia, migraine, and depression that might present in different ways."

Cole and colleagues report their findings in the Sept. 28 issue of the online journal BMC Gastroenterology.

Common Cause of Pain Syndromes?

Cole, now an epidemiologist with i3 Drug Safety, is not an expert on irritable bowel syndrome. Reza Shaker, MD, is. Shaker, chief of gastroenterology and hepatology at the Medical College of Wisconsin, was not involved in the Cole study.

"Clinical observations of patients with pain syndromes indicate that we are dealing with a syndrome bigger than a single organ," Shaker tells WebMD. "These findings confirm these previous observations."

Shaker says people with irritable bowel syndrome and people with pain syndromes such as fibromyalgia and migraine have something in common. They all have nerve pathways which somehow have become vastly oversensitive to pain signals -- a process doctors call sensitization.

Perhaps, Shaker suggests, there's a common problem at the crossroads where these nerve pathways intersect.

"Is it possible that there is an event -- possibly an early life event -- that affects the crossroads of all these nerve pathways?" he asks. "In areas where these nerves cross, it could be that there is sensitization occurring, affecting different neural circuits."

Cole suggests that different doctors looking at the same underlying illness might make different diagnoses. A gastroenterologist, for example, might diagnose irritable bowel syndrome, while a rheumatologist might diagnose fibromyalgia.

This sounds a lot like the blind men who, on first encountering an elephant, declare it to be like a snake or a tree depending on whether they are touching the elephant's trunk or its leg. Shaker says this analogy is apt. But most doctors, he says, will examine the whole elephant, not just its parts.

"A professional doesn't just focus on one symptom. If we see irritable bowel syndrome along with noncardiac chest pain or fibromyalgia, then we tackle this," he says. "But we doctors need to have a more global picture of this, instead of pigeonholing our diagnosis according to our own specialty or subspecialty."