Do Biomarkers Predict Response to a Pediatric Chronic Pain Symptom Management Program?

Inclusion Criteria: * A child 7-12 years of age with a FGID will be recruited if the medical evaluation reveals no organic reason for the abdominal pain and the child has abdominal pain that meets the definition of a FGID (i.e., IBS, functional abdominal pain) according to the pediatric Rome III criteria (Rome IV will be substituted when validated). Parents and children must speak and understand English because of the psychological assessment and CBT requirements. Exclusion Criteria: * Children who have: had past bowel surgery; documented GI disorders (e.g., Crohn's disease); a serious chronic medical condition (e.g., diabetes); weight and/or height \< 2 SD for age; chronic conditions with GI symptoms (e.g., cystic fibrosis); autism spectrum disorder, significant developmental delay, psychosis, or a history of bipolar disorder; been treated with antibiotics/probiotics within 2 mo. (because of effects on gut microbiome analysis), and children who for some reason could not be randomized to the low FODMAP diet.Vegetarian; children who are currently on the FODMAP Diet or receiving CBT Children who speak only Spanish are not eligible because the Rome questionnaire and psychological testing are not available in Spanish. Despite this, a large proportion of the children enrolled will be Hispanic.