Study shows global prevalence of functional gastrointestinal disorders

For every ten adults in the world, four suffer from functional gastrointestinal disorders of varying severity. This is shown by a study of more than 73,000 people in 33 countries. University of Gothenburg scientists are among those now presenting these results.

Functional gastrointestinal disorders, FGIDs, is a collective term for chronic disorders in the gastrointestinal tract, with severe symptoms, for which clear explanations or connections with objective findings from routine investigations are lacking.

The symptoms may arise throughout the gastrointestinal tract. From the upper part, the esophagus and stomach, they can include heartburn, acid reflux and indigestion (dyspepsia). In everyday parlance, the latter is often called "a sensitive stomach" or "gastritis," although there is no stomach inflammation. For the lower parts (the intestines), chronic constipation, abdominal distension or bloating, and irritable bowel syndrome (IBS) are among the complaints.

The present study, published in the journal Gastroenterology, gives an overall picture of the global prevalence of FGIDs. Data were collected by means of web-based questionnaires and face-to-face (household) interviews.

Striking international similarities

Magnus Simrén, Professor of Gastroenterology at Sahlgrenska Academy, University of Gothenburg, belongs to the international steering group for the study and is in charge of its Swedish part, comprising 2,000 people.

It's striking how similar the findings are between countries. We can see some variations but, in general, these disorders are equally common whatever the country or continent."

Magnus Simrén, Professor of Gastroenterology at Sahlgrenska Academy, University of Gothenburg

The questions posed to the respondents were based on the diagnostic criteria for IBS and other FGIDs. Particulars of other diseases and symptoms, living conditions, quality of life, healthcare consumption, etc. were also requested.

The prevalence of FGIDs was higher in women than in men, and clearly associated with lower quality of life. According to the questionnaire responses, 49 percent of the women and 37 percent of the men met the diagnostic criteria for at least one FGID.

More studies underway

The severity of the disorders varied, from mild discomfort to symptoms that adversely affected quality of life to a high degree. The prevalence of FGIDs was also strongly associated with high consumption of healthcare, such as visits to the doctor and use of medication, but also surgery.

Web-based questionnaires were used in most of the countries in the study, including Sweden. In some countries, instead, the respondents were asked to reply to the questions when an interviewer read them aloud. In two countries, both methods were used in parallel, and the interviewees were found to report fewer symptoms.

"We don't know why we're seeing this difference, but one reason might be that people think it's embarrassing to talk about stomach and bowel symptoms to someone sitting in front of them, and that they therefore underreport them compared with those who give their responses anonymously on an online form," Simrén says.

The study is the first of a series in this area. The initiative for the massive data collection came from the Rome Foundation, a committee to which Magnus Simrén belongs, which develops diagnostic criteria for FGIDs.