Over a 3-year period, study nurses approached 400 consecutive
patients (ages 8–17 years) and their caretakers
during their initial visit to the abdominal pain clinic.
Patients with known organic gastrointestinal disease,
previous abdominal surgery, or other significant chronic
illness were excluded. Families were required to be English-
speaking. If the patient was eligible and the family
expressed interest, parental informed consent/permission
and child assent were obtained. Approximately 75% of
eligible families agreed to participate. The majority of
nonparticipants cited lack of time as the reason for
refusal. This study was completed as part of a long
(2–3 hour) evaluation visit and nonparticipating families
did not appear systematically different from consenting
families. Of the original 300 participants completing the
study, 17 children were excluded from analyses when
organic findings later were discovered via endoscopy
with biopsy, yielding a final sample of 283 participating
families.