Faculty Brief Bio

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

Chair, Division of Gastroenterology and Hepatology

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, colonoscopy, PEG and PEG/J, push enteroscopy, EGD with dilations (CRE balloon and achalasia)

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)

Joseph David, MD

Joseph David, MD

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, San Diego
Gastroenterology Fellowship: University of Pittsburgh Medical Center
Specialties: Endoscopic ultrasound, ERCP, endoscopic mucosal resection, radiofrequency ablation, balloon-assisted enteroscopy

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)​

Barbara J. MacCollum, MD

Barbara J. MacCollum, MD

Undergraduate: Arizona State University
Medical School: University of Arizona College of Medicine – Tucson
Internal Medicine Residency: Maricopa Medical Center
Gastroenterology Fellowship: Maricopa Medical Center/Good Samaritan 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
Specialities: Endoscopic ultrasound, ERCP, endoscopic mucosal resection, radio frequency ablation, balloon-assisted enteroscopy, endoscopic submucosal dissection

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

Teodor Pitea, MD

Teodor Pitea, MD

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

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
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 J. Schwartz, MD

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

Medical School: University of Wisconsin School of Medicine and Public Health
Internal Medicine Residency: Washington University School of Medicine/Barnes-Jewish Hospital
Gastroenterology Fellowship: Washington University School of Medicine/Barnes-Jewish Hospital
Transplant Hepatology Fellowship: Washington University School of Medicine/Barnes-Jewish Hospital
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