1. UCLA Center for Inflammatory Bowel Diseases, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, USA.
2. Leiden University Medical Center, Department of Digestive Diseases, Leiden, The Netherlands.
3. Cedars-Sinai Center for Outcomes Research and Education (CS-CORE), Division of Health Services Research, Cedars-Sinai Medical Center, Los Angeles, California, USA.
4. UCLA Department of Surgery, David Geffen School of Medicine, University of California at Los Angeles, California, USA.
5. Department of Colon and Rectal Surgery, Mayo Clinic, Rochester, Minnesota, USA.