Pediatric disorders of gut-brain interaction (DGBIs) comprise chronic or recurrent symptom-based gastrointestinal conditions that cannot be fully explained by identifiable structural, biochemical, or organic abnormalities after appropriate clinical evaluation. The term DGBI is used throughout this review in accordance with current terminology, whereas the historical term "functional gastrointestinal disorders" (FGIDs) is retained only when referring to studies that used earlier Rome classifications. This review examines the impact of four modifiable factors-sleep, psychological stress, circadian rhythm, and diet-on their development and severity in children and adolescents. Relevant literature was identified through PubMed, with emphasis on recent pediatric studies, systematic reviews, and meta-analyses. Sleep disturbances are associated with greater abdominal pain, functional disability, and impaired daytime functioning. Stress may exacerbate symptoms through hypothalamic-pituitary-adrenal axis activation, autonomic imbalance, altered motility, and visceral hypersensitivity. Circadian disruption may affect gastrointestinal motility, barrier function, enteroendocrine signaling, and microbial rhythmicity, although pediatric evidence remains limited. Diet influences fermentation, microbiota, intestinal permeability, and symptom expression, with regular meals, adequate hydration, and appropriate fiber intake representing important initial measures. These factors interact bidirectionally through shared neuroendocrine, autonomic, immune, and microbial pathways. Clinical management should therefore adopt a biopsychosocial, multidisciplinary approach combining symptom management with modification of sleep, stress, circadian habits, and dietary patterns. Further prospective pediatric studies are needed to clarify causality and support personalized interventions.