Irritable Bowel Syndrome Rates Might Be Lower Than Previously Thought

The global prevalence of irritable bowel syndrome (IBS) could be lower based on how stringent a criteria researchers use.

A team, led by Priya Oka, MBBS, Leeds Gastroenterology Institute, St James's University Hospital, determined the true global prevalence of irritable bowel syndrome.

While IBS represents one of the most common functional bowel disorders, community prevalence can vary widely between different countries. This variation might be explained by previous cross-sectional surveys that neither applied uniform diagnostic criteria or used identical methodology, rather than being due to true global variability.

In the systematic review and meta-analysis, the investigators identified data from all population-based studies using relatively uniform methodology. These studies used only the most recent iterations of the Rome criteria—Rome III and Rome IV.

The team searched several databases to identify cross-sectional surveys reporting the prevalence of irritable bowel syndrome in adults, according to the Rome III or Rome IV criteria.

The researchers also performed a manual search of a selection of conference proceedings for relevant abstracts published between 2006-2019.

They then extracted the prevalence data for all found studies, according to the criteria used to define the presence of IBS. In the meta-analysis, the investigators estimated pooled prevalence rates, according to study location and certain other characteristics such as sex and IBS subtype.

Overall, they identified 4143 citations, of which 57 studies were deemed eligible involving 92 separate adult populations totaling 423,362 participants. The pooled disease prevalence of IBS in the 53 studies from 38 countries involving 395,385 participants using the Rome III criteria was 9.2% (95% CI, 7.6-10.8; I 2= 99.7%).

On the other hand, the pooled IBS prevalence from 6 studies in 34 countries involving 82,476 individuals using the Rome IV criteria was 3.8% (95% CI, 3.1-4.5; I 2= 96.6%).

The investigators discovered that IBS mixed bowel habit was the most common subtype in the Rome III criteria studies. This was reported by 33.8% (95% CI, 27.8-40.0; 2=98.1%) of patients fulfilling criteria for IBS (ie, 3.7% [2·6–4·9] of all included participants had IBS-M).

However, IBS with diarrhea was the most common subtype with the Rome IV criteria (reported by 31.5% [95% CI, 23.2–40.5; I 2= 98.1% 61.6%] of people with IBS, corresponding to 1.4% [0.9–1.9] of all included participants having IBS-D).

The investigators also found higher rates of IBS in women than males (12.0% [95% CI, 9.3–15.0] vs 8.6% [6.3–11.2]; OR, 1.46 [95% CI, 1.33–1.59]).

Prevalence also varied significantly between individual countries. This variability persisted even when the same diagnostic criteria was applied and identical methodology was using in studies.

“Even when uniform symptom-based criteria are applied, based on identical methodology, to define the presence of IBS, prevalence varies substantially between countries,” the authors wrote. “Prevalence was substantially lower with the Rome IV criteria, suggesting that these more restrictive criteria might be less suitable than Rome III for population-based epidemiological surveys.”

The study, “Global prevalence of irritable bowel syndrome according to Rome III or IV criteria: a systematic review and meta-analysis,” was published online in The Lancet Gastroenterology & Hepatology.