1. Department of Pediatrics, Päijät-Häme Central Hospital, Lahti, Finland
2. Section of Pediatric Surgery, New Children’s Hospital, Helsinki University Hospital, Helsinki, Finland
3. Radiology, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
4. Pediatric Gastroenterology Unit, New Children’s Hospital, Helsinki University Hospital, Helsinki, Finland
5. Department of Pediatric Surgery, Karolinska Institutet, Stockholm, Sweden.