Figure 1 illustrates the course of the RCT. Patients were
recruited consecutively from an ongoing epidemiological
examination concerning learning disabilities in schoolchildren.
An initial screening focusing on the frequency and
trigger mechanisms of abdominal pain was performed to
identify potentially affected children. The screening criteria
(e.g., child suffered from abdominal pain at least once a
week without organic findings) were fulfilled by 144 children
between the ages of 7 and 12 years. In the next step,
these potentially affected children, and their parents were
invited to a comprehensive diagnostic assessment (T1) to
validate the self-report data