1. Division of Gastroenterology, Carl T. Hayden VA Medical Center, 650 E. Indian School Road, Phoenix, AZ 85012, USA
2. Division of Gastroenterology, Mayo Clinic, 13400 East Shea Boulevard, Scottsdale, AZ 85259, USA
3. Division of Gastroenterology, Arizona Center for Digestive Health, 2680 S. Val Vista, Suite 116, Gilbert, AZ 85295, USA
4. Division of Gastroenterology, University of New Mexico, 1 University Boulevard of New Mexico, Albuquerque, NM 87131, USA