Abdominal Pain in Children: A Comprehensive Review of Functional and Organic Etiologies, Pathophysiology, Diagnostic Approach, and Management

Abdominal pain is among the most common complaints encountered in pediatric clinical practice and remains a frequent cause of outpatient visits, emergency department presentations, and hospital admissions. The clinical spectrum of abdominal pain in children is broad, ranging from benign, self-limiting functional disorders to serious organic and surgical conditions requiring urgent intervention. Distinguishing functional abdominal pain from organic pathology poses a significant diagnostic challenge and often leads to excessive investigations, parental anxiety, and increased healthcare utilization. Advances in understanding pediatric gastrointestinal physiology, neuroenteric signaling, and psychosocial influences have reshaped the conceptual framework of abdominal pain, particularly functional abdominal pain disorders. This review provides a comprehensive overview of abdominal pain in children, encompassing epidemiology, classification, etiological factors, underlying pathophysiological mechanisms, structured clinical evaluation, red-flag features, rational investigation strategies, and evidence-based management approaches. Emphasis is placed on the biopsychosocial model and the gut brain axis, which are central to understanding functional abdominal pain. This article aims to serve as a detailed reference for pediatricians, researchers, and healthcare professionals involved in the care of children with abdominal pain.