aVatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine at UCLA, Greater Los Angeles VA, Los Angeles

bDigestive Health Institute, University of California, Irvine, California, USA

Correspondence to Kenneth J. Chang, MD, MASGE, AGAF, FACG, FJGES, Executive Director, Digestive Health Institute, Chief, Division of Gastroenterology and Hepatology, Building 22C, 3rd Floor, RT 99, Rm. 106, 101 The City Drive, Orange, CA 92868, USA. Tel: +1 714 456 6187; fax: +1 714 456 7520; e-mail: [email protected]