1 Division of Gastroenterology, Duke University Medical Center, Durham, North Carolina; Durham Veterans Affairs Health Care System, Durham, North Carolina.
2 Division of Gastroenterology, Duke University Medical Center, Durham, North Carolina.
3 Division of Gastroenterology, Duke University Medical Center, Durham, North Carolina; Durham Veterans Affairs Health Care System, Durham, North Carolina. Electronic address: Ziad.gellad@duke.edu.