Researchers in Gothenburg, among others, have collected survey and interview responses from just over 73,000 people in 33 countries.

It was found that four out of ten adults may have IBS, chronic constipation or any of the other diseases included in the collective concept of functional gastrointestinal disease.

"We knew that it was very common, but that it is so common we might not have thought," says Magnus Simrén, a professor of medical gastroenterology at the Sahlgrenska Academy at the University of Gothenburg.

- But it ranges from fairly mild symptoms to people who need care because of their problems. As a group, these people consume a great deal of healthcare, but there is a great range within the group.

More women

The survey was conducted partly through a web survey, which, among other things, about 2,000 people in Sweden responded to, and partly through interviews.

Of the respondents who answered via a network, 40.7 percent (49 percent of women and 37 percent of men) met the diagnostic criteria for at least one functional gastrointestinal disease.

At the same time, the countries that used interviews to collect the data received a significantly lower proportion (20.9 percent). According to Magnus Simrén, one of the conceivable explanations is that it can be perceived as embarrassing to tell about your gastrointestinal symptoms and that it is therefore under-reported compared to the anonymous web responses.

"All continents"

Apart from that, the figures in the survey are strikingly similar, no matter what country it is about, he notes.

- It has been thought that this may only exist in the western world, but what we see is that it exists to the same extent in countries in all continents.

- It is likely that many of the factors that we believe can affect, such as stress and how we eat, are becoming more and more equal across the world.

The study has been published in the journal Gastroenterology.