1. Division of Gastroenterology and Hepatology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA;
2. Department of General Surgery, Digestive Disease Surgical Institute, Cleveland Clinic, Cleveland, Ohio, USA;
3. Division of Colorectal Surgery, Cedars Sinai Medical Center, Los Angeles, California, USA;
4. Inflammatory Bowel Disease Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA.