Department of Paediatrics of Medicine of Colombo 00800 Lanka;
University Paediatric Unit Ridgeway Hospital for Children 00800 Lanka;
Department of Physiology of Medicine of Kelaniya 11010 Lanka;
Department of Pediatric Gastroenterology and Nutrition Children Hospital University Medical Center 1105AZ Netherlands;
CONSTIPATION; CHILDREN; Functional gastrointestinal disorders; Psychological stress; TREATMENT; Surgical interventions;