Health-related quality of life in youth with abdominal pain: An examination of optimism and pain self-efficacy

•Abdominal pain impacts many children with gastrointestinal illnesses.•Relation between functional/organic diagnosis and well-being is not clear.•Research focuses on factors impeding functioning vs. those promoting flourishing.•We found pain self-efficacy and optimism related to better quality of life (QoL).•Diagnosis didn't explain relations between optimism/pain self-efficacy and QOL.