1. Department of Gastroenterology, Kaiser Permanente San Francisco Medical Center, San Francisco, California, United States
2. Kaiser Permanente Division of Research, Oakland, California, United States
3. Division of Gastroenterology, University of California, San Francisco, San Francisco, California, United States
4. Division of Gastroenterology, City of Hope National Medical Center, Duarte, California, United States
5. San Francisco Veterans Affairs Healthcare System, San Francisco, California, United States
6. Division of Gastroenterology, Palo Alto Medical Foundation, Palo Alto, California, United States
7. Advanced Gastrointestinal Endoscopy, Mountain View, California, United States