Doctors use special checklists to find out if someone has stomach pain that has no clear cause. These checklists are called Rome criteria. A large study looked at how many people have these problems using two different versions of the checklist. The older version is called Rome III, and the newer one is Rome IV.
When doctors used the older Rome III rules, about 12 out of every 100 people were found to have these stomach issues. However, when they used the newer Rome IV rules, only about 8 out of every 100 people qualified. This means the new rules are harder to meet, so fewer people get the diagnosis.
The study also looked at specific types of stomach pain. For example, one type affects about one in 23 people, while another affects only one in 68. Girls were found to have these problems more often than boys. Because the rules changed, the numbers we see today might be lower than they really are.
This is important because it shows how changing the checklist changes the count of sick people. Doctors need to know this so they do not worry too much if fewer people are diagnosed now. The real number of people with these problems is probably somewhere in the middle of the two counts.