Irritable Bowel Syndrome

Background: Irritable bowel syndromehas a high prevalence. Consensus
diagnostic criteria (ROME II) based on symptoms have been established to
aid diagnosis. Although coeliac disease can be misdiagnosed as irritable
bowel syndrome, no prospective study has been published in which patients
with this disorder are investigated for coeliac disease. We aimed to assess
the association of coeliac disease with irritable bowel syndrome in
patients fulfilling ROME II criteria.

Methods: We undertook a case-control study at a university hospital. 300
consecutive new patients who fulfilled Rome II criteria for irritable bowel
syndrome, and 300 healthy controls (age and sex matched) were investigated
for coeliac disease by analysis of serum IgA antigliadin, IgG antigliadin,
and endomysial antibodies (EMA). Patients and controls with positive
antibody results were offered duodenal biopsy to confirm the possibility of
coeliac disease.

Findings: 66 patients with irritable bowel syndrome had positive antibody
results, of whom 14 had coeliac disease (11 EMA positive, three EMA
negative). Nine patients with positive antibody results were lost to
follow-up or refused biopsy (only one EMA-positive patient refused biopsy),
and 43 had normal duodenal mucosa. Two controls, both of whom were EMA
positive, had coeliac disease. Compared with matched controls, irritable
bowel syndrome was significantly associated with coeliac disease (p=0·004,
odds ratio=7·0 [95% CI 1·7-28·0]).

Interpretation: Patients with irritable bowel syndrome referred to
secondary care should be investigated routinely for coeliac disease. With
only EMA, three of 14 cases would have been missed.