Affiliations:
  1. Department of Pediatrics, Dokkyo Medical University, Tochigi, Japan
  2. Department of Gastroenterology, Dokkyo Medical University, Tochigi, Japan
  3. Department of Diagnostic Pathology, Dokkyo Medical University, Tochigi, Japan
  4. Masuyama Gastrointestinal Clinic, Tochigi, Japan