Jump to: Page Content, Site Navigation, Site Search,
You are seeing this message because your web browser does not support basic web standards. Find out more about why this message is appearing and what you can do to make your experience on this site better.
Luis A García Rodríguez Centro Español de Investigación
Farmaco- epidemiológica, Madrid 28004, Spain
Correspondence to: Dr Rodríguez
lagarcia{at}ceife.es
Evidence exists of an increased risk of irritable bowel
syndrome after an episode of bacterial
gastroenteritis.
1 2
In one study, 12 out of 38 patients
presented with bowel dysfunction 1 year after salmonella
gastroenteritis.1 In another study, 386 patients with
bacterial gastroenteritis were surveyed by questionnaire 6 months after
infection, and 27 (7%) had developed irritable bowel
syndrome.2 Both studies, however, lacked a control
group.3
Our source population came from the General Practice Research
Database, which contains clinical information on patients recorded by
general practitioners in the United Kingdom.4
We identified patients aged 25 to 74 with a bacteriologically confirmed
first episode of gastroenteritis, from a recent study that examined
the association between acid suppressing drugs and the development of
gastroenteritis.5 We excluded all patients with a history
of irritable bowel syndrome, cancer, or alcoholism. We sampled a
comparison cohort from the source population from which patients with
gastroenteritis had been ascertained. We applied the same eligibility
criteria as were used for the ascertainment of the gastroenteritis
cohort, but the subjects had to be free of gastroenteritis at the start
of follow up. We then followed up both cohorts during 1 year until the
earliest occurrence of one of the following end points: diagnosis of
irritable bowel syndrome, cancer, alcohol misuse, or death. To confirm
diagnoses, we sent a questionnaire to the doctors of all patients with
irritable bowel syndrome in the gastroenteritis cohort and a 10%
random sample (n=216) to the doctors of patients with irritable bowel syndrome in the general population. We used Poisson regression to
calculate incidence, relative risk, and 95% confidence intervals of
irritable bowel syndrome associated with gastroenteritis. The general
population cohort was used as the reference group, and the estimates
were adjusted for age, sex, and body mass index.
Our study included 584 308 subjects in the general population cohort
and 318 patients in the gastroenteritis cohort (table). During the
1 year follow up, 2027 (0.3%) subjects in the general population
cohort and 14 (4.4%) in the gastroenteritis cohort had a diagnosis of
irritable bowel syndrome recorded on computer. One hundred and sixty
nine subjects (78%) from the random sample of the general population
cohort, and 12 (86%) subjects in the gastroenteritis cohort, had
confirmed irritable bowel syndrome on the basis of the questionnaire.
We analysed all patients in the general population with a diagnosis of
irritable bowel syndrome recorded on computer and all cases confirmed
by the doctor in the gastroenteritis cohort. The adjusted relative risk
of irritable bowel syndrome was much higher in the gastroenteritis
cohort than in the general population cohort (difference 11.9, 95%
confidence interval 6.7 to 21.0).
We found that, in the year after an episode of gastroenteritis,
patients were 10 times more likely to have irritable bowel syndrome
than were subjects in the general population. All incident cases of
irritable bowel syndrome in the gastroenteritis cohort were confirmed
by the doctor, but we obtained only a random sample of patients with
irritable bowel syndrome in the general population owing to the large
number of cases (>2000 patients). When we adjusted for this, the
incidence of irritable bowel syndrome was reduced to 2.7 per 1000 per
year in the general population, and the crude relative risk associated
with gastroenteritis was increased to 14.4.
Only one other study has analysed the risk of irritable bowel syndrome
in an unselected group of patients with gastroenteritis.2 The authors estimated a rate of newly diagnosed irritable bowel syndrome of about 7%, similar to our finding (4%). Our study, however, is the first to include a control group and therefore to
provide estimates of relative risk.3 We conclude that
bacterial gastroenteritis is a major independent risk factor for
irritable bowel syndrome.
We thank the staff at the Epidemiology and Pharmacology
Information Centre, the doctors participating in the general practice research database, and Saga Johansson and Mari-Ann Wallander for providing the initial idea for the study and for commenting on the paper.
Contributors: LAGR designed the study protocol, participated in
data analysis, and wrote the paper; he will act as guarantor for the
paper. AR helped with data analysis and contributed to the paper.
Funding: None.
Competing interests: Research funds were provided for
the original study from which the gastroenteritis cohort was identified.
(Accepted 30 October 1998)
![]()
Subjects, methods, and results
Top
Subjects, methods, and results
Comment
References
![]()
Comment
Top
Subjects, methods, and results
Comment
References
![]()
Acknowledgments
![]()
References
Top
Subjects, methods, and results
Comment
References
post salmonella infection.
J Infect
1994;
29:
1-3[Medline].
© BMJ 1999
Read all Rapid Responses