Professor of Medicine, Weill Cornell Medical College

Professor of Medicine, Institute for Academic Medicine, Houston Methodist Hospital

 David M Underwood Chair of Medicine in Digestive Disorders, Houston Methodist Hospital

Co-Director, Lynda K and David M Underwood Center for Digestive Disorders, Houston Methodist Hospital

Chief, Division of Gastroenterology and Hepatology, Houston Methodist Hospital, Houston, TX

Adjunct Professor of Medicine, Texas A and M Health Sciences Center College of Medicine 

Adjunct Profeessor, School of Medicine, University College Cork, Cork, Ireland