About of gastroenteritis caused by bacteria or viruses can evolve into
irritable bowel syndrome (IBS). And when this happens, personality factors
seem to be involved, a new study suggests.
The research was conducted by Meagan Spence, Ph.D., an honorary lecturer in
occupational medicine at the University of Auckland in New Zealand, and by
Rona Moss-Morris, Ph.D., a professor of health psychology at the University of
Southampton in England. Results were published in the August Gut.
The study included 620 individuals who had visited their primary care
doctors because of symptoms of gastroenteritis and who had tested positive for
the Campylobacter bacterium. At the time of diagnosis, the
researchers had the subjects complete a questionnaire that included
standardized measures of mood, perceived stress, perfectionism, negative
illness beliefs, and illness behaviors. The researchers then followed the
subjects for six months to determine whether any developed IBS. Forty-nine
did. Finally, the researchers compared the psychological profiles of the 49
who developed IBS with the psychological profiles of the subjects who did not
develop IBS.
They found that subjects who developed IBS had significantly higher levels
of perceived stress, anxiety, and somatization at the time of
Campylobacter diagnosis than did those who did not develop IBS. They
also tended to see the consequences of having an infection as more distressing
and as having a greater impact on their lives than did the subjects who did
not get IBS. Furthermore, they were significantly more likely to remain active
while acutely ill until they felt forced to rest—what the researchers
called an "all-or-nothing response."
Thus, perceived stress, anxiety, and unrealistic personal expectations
appear to characterize those individuals who develop IBS following
gastroenteritis, the researchers believe. And such an outlook may persist once
a person has developed IBS, thereby perpetuating the condition.
In contrast, they found no more depression in the group that developed IBS
than in the group that did not, contrary to what some retrospective studies
have found. This is the result that may most interest psychiatrists, Spence
told Psychiatric News. It suggests that "depression may not be
as important as anxiety levels and more subtle psychological variables such as
illness beliefs and perceived stress [in development of IBS]. This result has
important implications for prevention and early intervention in the
development of IBS."
"I thought the study was very interesting," Steven Field, M.D.,
a New York City gastroenterologist who is studying to become a psychodynamic
psychotherapist, said in an interview. "I'm not surprised that
[gastroenteritis-provoked IBS] is correlated more with anxiety than with
depression. Most IBS patients tend to be more anxious than depressed, in my
experience."
When asked whether the results of the study also apply to IBS patients
whose IBS is not triggered by a bout of gastroenteritis, Field said, "I
think they do, because it shows that personality can be a substrate for the
development of these symptoms."
IBS patients could benefit from cognitive-behavioral therapy, Spence and
Moss-Morris said. Field agreed. In fact, "cognitive-behavioral therapy
is used in many instances for the treatment of IBS," he said.
The study was funded by the University of Auckland.
An abstract of "The Cognitive Behavioral Model of Irritable
Bowel Syndrome: A Prospective Investigation of Patients with
Gastroenteritis" is posted at<http://gut.bmj.com/cgi/content/abstract/56/8/1066>.▪