1 Anatomical Pathology, Cleveland Clinic, Cleveland, Ohio, USA.
2 Gastroenterology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
3 Gastroenterology and Hepatology, Veterans Affairs Medical Center, Kansas City, Missouri, USA; Gastroenterology, University of Kansas School of Medicine, Kansas City, Kansas, USA.
4 Gastroenterology, Columbia University School of Medicine, New York, New York, USA.