1. Division of Pediatrics, Escuela de Medicina, Pontificia Universidad Católica de Chile; Gastroenterology and Nutrition Department; 85 Lira Santiago Region Metropolitana Chile 8330074
2. Escuela de Medicina, Pontificia Universidad Católica de Chile; Gastroenterology and Nutrition Department, Division of Pediatrics; Santiago Chile
3. Faculty of Medicine, Pontificia Universidad Católica de Chile; Department of Public Health; Marcoleta 434 Santiago Chile 354-6894
4. Escuela de Medicina, Pontificia Universidad Católica de Chile; Santiago Chile
5. University of Alberta; Division of Pediatric Gastroenterology, Hepatology and Nutrition, Dept. of Pediatrics, Stollery Children's Hospital, Faculty of Medicine; Aberhart Centre 1 11402 University Ave Edmonton AB Canada T6G 2J3