Irritable Bowel Syndrome Runs in Family

Nature or Nurture? IBS Patients Have More IBS Relatives

From the WebMD Archives

Dec. 18, 2003 -- Irritable bowel syndrome runs in families, a telephone survey indicates.

Irritable bowel syndrome isn't a single disease. It's a collection of symptoms that include abdominal pain or discomfort and constipation and/or diarrhea -- as many as one in five Americans reports some of these symptoms. They can significantly affect a person's quality of life.

Where does it come from? A team of Mayo Clinic researchers is looking at the possibility of a genetic link. In earlier work, they found that a person who reports having a family member with irritable bowel syndrome symptoms is more than twice as likely as other people to experience similar symptoms.

The researchers polled family members of patients with irritable bowel syndrome. They also polled the families of the patients' symptom-free spouses. The result: While 17% of patients' had relatives with irritable bowel syndrome, only 7% of the spouses had such a relative.

"The next challenge is determining nature versus nurture," study co-researcher G. Richard Locke, MD, says in a news release. "Is this due to a gene or genes, or is it due to a shared environmental factor? Our group is actively investigating these issues."

The findings appear in the December issue of Gut.

Two studies have shown that the identical twins of irritable bowel syndrome patients are more likely to have the condition than fraternal twins of patients. But other twin studies show evidence that what individuals learn from their environments has at least as much impact on irritable bowel syndrome as heredity.