What Is IBS?
- IBS with constipation (IBS-C)
- IBS with diarrhea (IBS-D)
- IBS with mixed bowel habits (IBS-M)
- IBS with unclassified bowel habits (IBS-U)
How Common Is IBS?
It’s important to know that if you’re struggling with IBS, you’re not alone. To set the stage for how enormous and challenging of a problem IBS is for so many people, let’s talk about IBS prevalence data.
We’ll warn you ahead of time that there is some variation in the prevalence data and statistics depending on which version of the Rome criteria was used in a given study. This happens for several reasons.
One of those reasons is that when updates are made, the criteria can be more strict or less ‘strict,’ which may increase or decrease the number of people that meet the criteria for IBS. Differences in prevalence data are also due to the varying number of studies available from each version of the criteria.
Because of this, in the graphic below, we use data from the Rome III criteria rather than the Rome IV, as there are not as many prevalence studies available yet where the Rome IV is used.

Summary
- IBS is a chronic and common disorder of gut-brain interaction.
- IBS is defined by pain with defecation or a change in bowel habits.
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There are 4 subtypes of IBS:
- IBS with constipation (IBS-C)
- IBS with diarrhea (IBS-D)
- IBS with mixed bowel habits (IBS-M)
- IBS with unclassified bowel habits (IBS-U)
- IBS subtypes are defined by using diagnostic criteria developed by the Rome Foundation.
- Prevalence rates of IBS differ around the world and change based on which Rome criteria is used.
- It is estimated that about 9.2% of the world’s population suffers from IBS, with women being more likely to have IBS than men.