1. Department of Gastroenterology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
2. Instructor, Department of Surgery, Division of Endoluminal Surgery & Interventional Gastroenterology, University of Texas Health Science Center, Houston, TX 77030, USA
3. Department of Gastroenterology and Hepatology, Kansas City VA Medical Center, 4801 Linwood Blvd, Kansas City, MO 64128, USA