Faculty  Personal Bio

Stacie Vela, MD, FASGE
Stacie Vela, MD, FASGE

Chief, Gastroenterology Section, Carl T. Hayden VA Medical Center
Program Director, Gastroenterology Fellowship

Medical School: The Ohio State University
Residency: University Hospitals/Case Western University
GI Fellowship: Medical University of South Carolina
Specialties: Endoscopic teaching, pancreatic diseases, gastrointestinal cancers and advanced endoscopic techniques, such as endoscopic ultrasound and endoscopic mucosal resection  

Stacie Vela, MD, FASGE
Sushovan Guha, MD, PhD

Associate Program Director, Gastroenterology fellowship Program
Chair, Division of Gastroenterology and Hepatology
Professor, Department of Medicine, University of Arizona College of Medicine – Phoenix
Physician Executive Director, Banner Digestive Diseases Institute

Medical School: JIPMER, University of Madras
Internal Medicine Residency: Albert Einstein College of Medicine Hospitals
Gastroenterology Fellowship: UCLA
PhD: Molecular Biology Institute, UCLA
Specialties: General GI, GI bleed, pancreatic diseases, upper GI endoscopy (EGD) – diagnostic and therapeutic

Yasmin Alishahi 
Yasmin Alishahi, MD, FACG

Staff Gastroenterologist, Carl T. Hayden VA Medical Center
Clinical Assistant Professor of Medicine, UA College of Medicine – Phoenix

Medical School: University of Tennessee Health Science Center College of Medicine
Residency: University of Tennessee Health Science Center College of Medicine
Chief Residency: University of Tennessee Health Science Center College of Medicine
GI Fellowship: University of Texas Health Science Center
Specialties: Diagnosis and disease activity assessment of inflammatory bowel disease, medical therapy of inflammatory bowel disease, health preventive measures in patients with ulcerative colitis and Crohn's Disease, in particular in patients on immunosuppressive therapy

Paul J. Berggreen, MD

Paul J. Berggreen, MD

Undergraduate: Louisiana State University
Medical School: Louisiana State University School of Medicine
Internal Medicine Residency: Banner – University Medical Center Phoenix, Carl T. Hayden Phoenix VA Medical Center
Gastroenterology Fellowship: Carl T. Hayden Phoenix VA Health Care System, UA College of Medicine – Phoenix
Specialties: ERCP, open access colonoscopy, therapeutic endoscopy, upper GI endoscopy (EGD)

​Mashal Jatoi Batheja, MD
​Mashal Jatoi Batheja, MD

Chief, Hepatology, Carl T. Hayden VA Medical Center
Clinical Assistant Professor of Medicine, UA College of Medicine – Phoenix

Medical School: University of Southern California
Internship and Residency: Northwestern University
Transplant Hepatology Fellowship: Mayo Clinic, Scottsdale, AZ
Gastroenterology Fellowship: Mayo Clinic, Scottsdale, AZ
Specialties: Chronic liver diseases, non-invasive testing for liver fibrosis, management of Hepatitis C, nonalcoholic fatty liver disease and hepatocellular carcinoma

Joseph David, MD
Joseph David, MD

Site Director, Gastroenterology Fellowship, Banner – University Medical Center Phoenix
Clinical Assistant Professor, UA College of Medicine – Phoenix

Undergraduate: University of Missouri
Medical School: University of Missouri
Internal Medicine Residency: Good Samaritan Regional Medical Center
Gastroenterology Fellowship: Good Samaritan Regional Medical Center
Specialties: ERCP, open access colonoscopy, upper GI endoscopy (EGD)

Brenda Dennert, MD

Brenda Dennert, MD

Undergraduate: San Francisco State University
Medical School: University of Southern California
Internal Medicine Residency: Santa Clara Valley Medical Center
Gastroenterology Fellowship: University of Arizona/Carl T Hayden VA Medical Center
Specialties: Colonoscopy, ERCP, pH Monitoring, upper GI endoscopy (EGD)​

David J. Drewitz, MD

David J. Drewitz, MD

Undergraduate: University of Wisconsin
Medical School: Medical College of Wisconsin
Internal Medicine Residency: St Joseph’s Hospital and Medical Center
Gastroenterology Fellowship: Carl T. Hayden Phoenix VA Medical Center
Specialties: Capsule endoscopy, colonoscopy now, ERCP, hepatology and liver disease, nutrition, Remicade® infusion, therapeutic endoscopy, upper GI endoscopy (EGD)

Michael Fallon, MD

Michael Fallon, MD

Medical School: University of Virginia School of Medicine
Internal Medicine Residency: Yale New Haven Hospital
Gastroenterology Fellowship: Yale University School of Medicine
Specialties: Complications of cirrhosis, portal hypertension management, liver transplant evaluation, chronic liver disease, upper and lower endoscopy

Charles Gabbert, MD

Charles Gabbert, MD

Medical School: Oregon Health and Sciences University
Internal Medicine/Pediatrics Residency: University of California
Gastroenterology Fellowship: University of Pittsburgh Medical Center
Specialties: Endoscopic Ultrasound, ERCP, endoscopic mucosal resection, radiofrequency ablation, balloon-assisted enteroscopy

Richard Gerkin, MD
Richard Gerkin, MD

Medical Director of GME Research, Banner – University Medical Center Phoenix
Clinical Associate Professor of Medicine, UA College of Medicine – Phoenix

Medical School: UA College of Medicine – Tucson
Residency and Cardiology Fellowship: Banner – University Medical Center Phoenix (Formerly Banner Good Samaritan Medical Center)
Specialties: Assisting in research design, IRB submission, statistical analysis and manuscript preparation of studies for faculty and fellows in the GI Fellowship

Aaron Goldberg, MD
Aaron Goldberg, MD

Staff Gastroenterologist, Carl T. Hayden VA Medical Center
Clinical Assistant Professor, UA College of Medicine – Phoenix

Medical School: UA College of Medicine – Tucson
Residency: Beth Israel Deaconess Medical Center
GI Fellowship: Banner – University Medical Center Phoenix (Formerly Banner Good Samaritan Medical Center)
Specialties: Endoscopic ultrasound, inflammatory bowel disease, Barrett’s esophagus and colorectal cancer prevention

Vincent J. Honan, MD

Vincent J. Honan, MD

Undergraduate: State University of New York
Medical School: Albany Medical College of Union University
Internal Medicine Residency: Westchester County Medical Center
Gastroenterology Fellowship: University of Arizona, Maricopa County Medical Center/Good Samaritan Regional Medical Center
Specialties: Barrx ablation, capsule endoscopy, ERCP, open access colonoscopy, pH monitoring, upper GI endoscopy (EGD)​

Camron Kiafar, DO, AGAF, FACG
Camron Kiafar, DO, AGAF, FACG

Chief of Endoscopy, Carl T. Hayden VA Medical Center
Clinical Assistant Professor, UA College of Medicine – Phoenix

Medical School: Western University of Health Sciences
Residency and GI Fellowship: Banner – University Medical Center Phoenix (Formerly Banner Good Samaritan Medical Center)
Specialties: Endoscopic eradication of Barrett’s esophagus, colorectal cancer prevention and GI malignancies

Geetha Kolli, MD

Geetha Kolli, MD

Medical School: Indira Gandhi Medical College
Internal Medicine Residency: Conemaugh Memorial Medical Center
Hepatology Residency: Banner – University Medical Center Phoenix
Specialties: Autoimmune live disease, liver diseases in pregnancy

Derek Landan, MD
Derek Landan, MD

Staff Gastroenterologist, Carl T. Hayden VA Medical Center

Medical School: Northeastern Ohio University College of Medicine 
Residency: Summa Health System/Northeastern Ohio University 
GI Fellowship: Banner – University Medical Center Phoenix (Formerly Banner Good Samaritan Medical Center)
Specialties: Endoscopic ultrasound and biliary endoscopy

Ester Little, MD​

Ester Little, MD​

Transplant Hepatologist, Banner Transplant Institute
Clinical Assistant Professor, UA College of Medicine – Phoenix

Medical School: Faculdade de Ciencias Medicina De Santos
Internal Medicine Internship: Banner – University Medical Center Phoenix
Internal Medicine Residency: Banner – University Medical Center Phoenix
Specialties: Cholestatic liver disease, post-liver transplant care

Barbara J. MacCollum, MD
Barbara MacCollum, MD

Arizona Digestive Health/Banner – University Medical Center Phoenix

Undergraduate: Arizona State University
Medical School: University of Arizona College of Medicine – Tucson
Internal Medicine Residency: Maricopa Medical Center
Gastroenterology Fellowship: Maricopa Medical Center
Specialties: Colonoscopy, ERCP, upper GI endoscopy (EGD)

Shivang Mehta, MD

Shivang Mehta, MD

Medical School: Texas Tech University Health Science Center
Internal Medicine Residency: University of Texas at Houston
Gastroenterology Fellowship: University of Texas MD Anderson Cancer Center
Transplant Hepatology Fellowship: Mayo Clinic
Specialties: Liver transplant evaluation and post care, cirrhosis, Hepatitis C, Hepatitis B, NASH, PBC, general GI

Michael R. Mills, MD

Michael R. Mills, MD, MPH

Undergraduate: University of Arizona
Graduate: Tulane University School of Public Health and Tropical Medicine
Medical School: Tulane University School of Medicine
Internal Medicine Residency: University of Colorado School of Medicine
Gastroenterology Fellowship: University of Arizona Health Sciences Center, Carl T. Hayden VA Medical Center, Banner Good Samaritan Regional Medical Center
Specialties: Capsule endoscopy, colonoscopy now, endoscopic ultrasonography (EUS), ERCP, esophageal manometery, GERD, Remicade® infusion, upper GI endoscopy (EGD)

Rawad Mounzer, MD

Rawad Mounzer, MD

Medical School: American University of Beirut
Internal Medicine Residency: University of Pittsburgh Medical Center
Gastroenterology Fellowship: University of Pittsburgh Medical Center, University of Colorado Health Sciences Center
Specialties: Endoscopic Ultrasound, ERCP, endoscopic mucosal resection, radiofrequency ablation, balloon-assisted enteroscopy, endoscopic submucosal dissection

Rakesh Nanda, MD, FACP, FACG
Rakesh Nanda, MD, FACP, FACG

Staff Gastroenterologist, Carl T. Hayden VA Medical Center
Assistant Professor of Clinical Medicine, UA College of Medicine – Phoenix

Medical School: Maulana Azad Medical College, Delhi University, New Delhi
Residency: Pune University
GI Fellowship: Delhi University, followed by training at the John Radcliffe Hospital, Oxford, England and Completed training at Kansas University Medical Center
Specialties: Endoscopic eradication of Barrett’s esophagus, nutrition

Bruce D. Noland, MD

Bruce D. Noland, MD

Undergraduate: Iowa State University
Medical School: University of Iowa College of Medicine
Internal Medicine Residency: Carl T Hayden VA Medical Center
Gastroenterology Fellowship: Carl T Hayden VA Medical Center, University of Arizona College of Medicine – Phoenix
Specialties: Colonoscopy now, ERCP, Remicade® infusion, upper GI endoscopy (EGD)

​Nayan Patel, DO, MPH
Nayan Patel, DO, MPH

Graduate: University of Medicine and Dentistry of New Jersey
Medical School: University of Medicine and Dentistry of New Jersey
Internal Medicine Residency: University of Medicine and Dentistry of New Jersey
Hepatology Fellowship: Banner – University Medical Center Phoenix
Gastroenterology Fellowship: Banner – University Medical Center Phoenix
Specialties: Liver transplant evaluation and post care, hepatocellular carcinoma, cirrhosis, viral hepatitis, endoscopy, fecal microbiota transplant

Hugo Pinillos, MD, FACG
Hugo Pinillos, MD, FACG

Staff Gastroenterologist, Carl T. Hayden VA Medical Center
Clinical Assistant Professor of Medicine, UA College of Medicine – Phoenix

Medical School: Francisco Marroquin University, Guatemala 
Residency: Michael Reese Hospital /University of Illinois at Chicago 
GI Fellowship: St Luke’s – Roosevelt Hospital Center/Columbia University
Clinical Hepatology Fellowship: Mount Sinai Medical Center
Specialties: Functional GI disorders, infectious GI diseases and capsule endoscopy

Teodor Cristian Pitea, MD
Teodor Cristian Pitea, MD

Banner Internvional Endoscopy, Banner – University Medical Center Phoenix

Medical School: Iuliu Hatieganu University of Medicine and Pharmacy
Internal Medicine Residency: St Luke’s Roosevelt Hospital Center
Gastroenterology Fellowship: St. Luke's Roosevelt Hospital Center
Advanced Endoscopy Fellowship: Winthrop-University Hospital
Specialties: EUS, ERCP, colonoscopy, endoscopic mucosal resection, EGD, radiofrequency ablation (RFA), endoscopic myotomy (POEM), endoscopic Zenker's Diverticulectomy, pancreatic endo therapy, ESWL for pancreatic stones, balloon enteroscopy

Alberto Ramos, MD
Alberto Ramos, MD

Clinical Assistant Professor of Medicine, UA College of Medicine – Phoenix

Medical School: Ponce School of Medicine
Internal Medicine Internship: Banner – University Medical Center Phoenix
Internal Medicine Residency: Banner – University Medical Center Phoenix
Specialties: Management of cirrhosis, hepatocellular cancer, upper and lower endoscopy

Adam C. Randolph, MD
Adam C. Randolph, MD

Undergraduate: University of Illinois
Medical School: Rush Medical College
Internal Medicine Residency: Banner – University Medical Center Phoenix (Formerly Banner Good Samaritan Medical Center)
Gastroenterology Fellowship: Banner – University Medical Center Phoenix, Carl T. Hayden Phoenix VA Medical Center
Specialties: Capsule endoscopy, colonoscopy now, ERCP, Remicade® infusion, upper GI endoscopy (EGD)

Shiva K. Ratuapli, MD

Shiva K. Ratuapli, MD

Medical School: Osmania Medical College
Internal Medicine Residency: Brookdale University Hospital and Medical Center
Advanced Fellowship in Gastroenterology Motility: Mayo Clinic Rochester
Gastroenterology Fellowship: Mayo Clinic Arizona
Specialties: Barrett's Esophagus, colonoscopy now, esophageal diseases, esophageal manometery, fecal transplant, hepatology and liver disease, pH monitoring, Remicade® infusion, smart pill, therapeutic endoscopy, upper GI endoscopy (EGD)

Douglas J. Schwartz, MD
Douglas Schwartz, MD

Arizona Digestive Health/Banner – University Medical Center Phoenix

Undergraduate: University of Maryland
Medical School: University of Maryland
Internal Medicine Residency: Good Samaritan Regional Medical Center
Gastroenterology Fellowship: Good Samaritan Regional Medical Center, Maricopa Medical Center
Specialties: Capsule endoscopy, colonoscopy, ERCP, open access colonoscopy, upper GI endoscopy (EGD)

Anil Seetharam, MD
Anil Seetharam, MD

Clinical Assistant Professor of Medicine, UA College of Medicine – Phoenix
Transplant Hepatologist, Banner Transplant Institute
 

Medical School: University of Wisconsin School of Medicine and Public Health
Internal Medicine Residency: Washington University School of Medicine
Gastroenterology Fellowship: Washington University School of Medicine
Transplant Hepatology Fellowship: Washington University School of Medicine
Specialties: Liver transplant evaluation and post care, viral hepatitis, non-alcoholic fatty liver disease, hepatocellular cancer, endoscopic management of portal hypertension

Richard P. Shaughnessy IV, DO

Richard P. Shaughnessy IV, DO

Undergraduate: University of Arizona
Medical School: Western University of Health Sciences
Internal Medicine Residency: Good Samaritan Regional Medical Center, Carl T. Hayden VA Medical Center
Gastroenterology Fellowship: Good Samaritan Regional Medical Center, Carl T. Hayden VA Medical Center
Specialties: Capsule endoscopy, Crohn's Disease, ERCP, open access colonoscopy, pH monitoring, ulcerative colitis, upper GI endoscopy (EGD)

Eugene F. Tharalson, MD
Eugene F. Tharalson, MD

Undergraduate: Seattle University
Medical School: Medical College of Wisconsin
Internal Medicine Residency: University of Arizona College of Medicine – Phoenix
Gastroenterology Fellowship: Carl T. Hayden Phoenix VA Medical Center
Specialties: Capsule endoscopy, colonoscopy now, ERCP, Remicade® infusion, smart pill, upper GI endoscopy (EGD)

Darrell D. Wadas, MD, FACG, FASGE, FACP

Darrell D. Wadas, MD, FACG, FASGE, FACP

Undergraduate: University of Colorado
Medical School: University of Colorado
Internal Medicine Residency: Good Samaritan Regional Medical Center
Gastroenterology Fellowship: Carl T. Hayden VA Medical Center
Specialties: Barrett's Esophagus, ERCP, open access colonoscopy, therapeutic endoscopy

Mark Wong, MD

Mark Wong, MD

Medical School: Loma Linda University School of Medicine
Internal Medicine Residency: Banner – University Medical Center Phoenix
Hepatology Fellowship: Banner – University Medical Center Phoenix
Specialties: Hepatitis B and Hepatitis C management, autoimmune liver disease, Wilson's Disease, cirrhosis, primary biliary cholangitis, primary sclerosing cholangitis, hereditary hemochromatosis, hepatocellular cancer

Michele Young, MD
Michele Young, MD

Chief, Department of Medicine, Carl T. Hayden VA Medical Center

Medical School: State University of New York at Stony Brook
Residency and GI Fellowship: University of Pittsburgh Medical Center
Specialties: GI motility, inflammatory bowel disease and colon cancer screening strategies