Marc J. Zuckerman, M.D.
Professor of Medicine
Chief, Division of Gastroenterology
Dr. Zuckerman graduated Phi Beta Kappa from the University of Rochester and went to Tufts University School of Medicine in Boston. He did his residency in medicine at Baystate Medical Center (Tufts) and his fellowship in gastroenterology at the Albert Einstein College of Medicine in New York.
Professional society membership includes being a fellow of the American Society for Gastrointestinal Endoscopy, the American College of Gastroenterology, the American Gastroenterological Association, the Infectious Diseases Society of America, and a member of the American Neurogastroenterology and Motility Society and the American Association for the Study of Liver Disease. He has been a member of the Educational Affairs Committee and the Practice Parameters Committees of the American College of Gastroenterology, the Standards of Practice Committee of the American Society of Gastrointestinal Endoscopy, and was involved in the publication of numerous national guidelines on gastrointestinal endoscopy. He is the author over 75 publications in the field of gastroenterology. Research interests include irritable bowel syndrome, gastroesophageal reflux disease, non-steroidal anti-inflammatory drugs and the gastrointestinal tract, and infectious complications of liver disease.
Dr. Zuckerman’s clinical interests include functional gastrointestinal disorders such as irritable bowel syndrome, gastrointestinal bleeding, diseases of the small bowel, colon cancer screening, and the endoscopic procedures of video capsule endoscopy and small bowel endoscopy.
Richard McCallum M.D.
Professor of Medicine
Division of Gastroenterology
Dr. McCallum, a native of Brisbane, Australia, attended the University of Queensland and the Queensland Medical School, earning his bachelor's degree and his M.D. He served a rotating internship at the Charity Hospital in New Orleans LSU service, and his residency in categorical internal medicine at Barnes Hospital, Washington University in St. Louis, Missouri. Dr. McCallum had fellowship training in gastroenterology at the Wadsworth Veterans Hospital and the University of California in Los Angeles. Following his fellowship, he was appointed, director of GI endoscopy and assistant professor at UCLA. In 1976, Dr. McCallum went to Yale University School of Medicine, Yale-New Haven Veterans Administration Hospital where he served as director of the gastroenterology diagnostic laboratories and rose to associate professor.
Dr. McCallum was recruited to the University of Virginia in September 1985 to become the Paul Janssen Professor of Medicine, and chief of the division of gastroenterology, hepatology, and nutrition for ten years. He then accepted the position of professor of medicine, chief of gastroenterology and hepatology at Kansas University Medical Center where he was also director of the Center for GI Nerve & Muscle Function & GI Motility. He was elected to the American Society for Clinical Investigation, and is also a fellow of the American College of Physicians, the Royal Australasian College of Physicians, and the American College of Gastroenterology. Dr. McCallum has published more than 390 articles in peer-reviewed scientific journals, 100 textbook chapters, and has edited 13 scientific textbooks. The most recent textbooks that he has co-edited are entitled "GI Motility Testing – A Laboratory and Office Handbook," a reference text in this field and "Gastroparesis: Pathophysiology, Presentations, and Treatment." He serves on the editorial boards of eight scientific publications and committees of the major gastroenterology associations in this country. He was president of the Southern Society for Clinical Investigation, International Electrogastrogram Society, Trustee of the American College of Gastroenterology, and received the Southern Medical Association Award for Original Research. Pharmaceutically supported research is conducted by his research team and original research has been supported with VA Merit Reviewing funding, Pharmaceutical, American Diabetes Association, Foundation Grants, Small Business NIH Awards and most recently NIH Grant funding as part of the NIH Consortium in Gastroparesis.
Dr. McCallum's research has been focused on the physiology, pathophysiology, and pharmacology of gastrointestinal smooth muscle relating to disorders of motility and functional bowel disease involving the esophagus, stomach, small bowel, and colon. He has been continuously funded by the NIH, American Diabetes Association, and industry grants. He has made major advances in diagnosis and treatment of gastroparesis, especially in diabetes. As founding chair of medicine, he built a nationally competitive department of medicine at TTUHSC El Paso, as well as advancing research funding and starting fellowship programs. For the last 20 years his pioneering efforts in the area of electrophysiology of the gut and, specifically, electrical pacing of the stomach resulted in new therapeutic concepts for nausea and vomiting. Other research contributions that continue are in the recognition of cyclic vomiting as a major new etiology of nausea and vomiting in adults, diagnosing and treating dumping syndrome and rumination syndrome as well as other gut motility problems, such as anorectal motility disorders and irritable bowel and the spectrum of small bowel bacterial overgrowth. Developing new pharmacologic and medical device therapies for these entities are also ongoing projects..
Roberta Romero MSN, R.N., FNP-C
Division of Gastroenterology
Ms. Romero received her Bachelor of Science in Nursing (BSN) from the University of Texas at El Paso (UTEP) in 1997. She went on to receive a Master of Science in Nursing (MSN) in Administration in 2005 from UTEP as well, and completed a post master's Family Nurse Practitioner Certificate program from Texas Tech University Health Sciences Center in Lubbock in 2009. Currently she is in the Doctor of Nursing Practice program through Texas Tech University Health Sciences Center in Lubbock, Texas and will complete May 2014. Her clinical experience includes administering a gastroenterology and hepatology clinic (mainly for hepatitis C treatment) and keeps close surveillance on lab work, diagnostic studies. She sees gastroenterology patients with percutaneous endoscopic gastrostomy tube issues, follow-up gastroenterology clinic patients, and follows up post procedure patients discharged from University Medical Center (UMC).
She is board certified through the American Association of Nurse Practitioners (AANP). Professional and Honorary Societies that she belongs to include: Sigma Theta Tau National Nursing Honor Society (STT), American Association of Nurse Practitioners (AANP), American Nurses Association (ANA), Texas Nurse's Association (TNA), American Society for Gastrointestinal Endoscopy (ASGE), and American College of Gastroenterology (ACG).
Ms. Romero created a hepatitis C support group in El Paso that meets the last Thursday of every month for patients and family members that have hepatitis C and are undergoing treatment or are thinking of undergoing treatment. Her research interests include hepatitis C treatment outcomes.
Gastroenterology Fellowship Program
Christine Yu, M.D.
Fellow in Gastroenterology
Medical School: Ross University School of Medicine, Roseau, Dominica, West Indies.
Residency: Saint Vincent's Catholic Medical Center- Manhattan New York, New York. Lennox Hill Hospital, New York City, New York.
Arleen Ortiz, M.D.
Fellow in Gastroenterology
Medical School: Ponce School of Medicine Puerto Rico, Ponce Puerto Rico.
Residency: Texas Tech University Health Sciences Center El Paso
Nancy Casner, M.S., CCRC
Gastroenterology Research Coordinator
Certified Clinical Research Coordinator
Nancy Casner received her B.S. degree from Empire State College – S.U.N.Y and her M.S. degree in community health and health administration from Long Island University, N.Y. Nancy has been involved in research in the GI division since 1985, first as lab technician, doing bench research with Marc Zuckerman, M.D., and then as a clinical research coordinator in the GI and rheumatology divisions, since 1987. In 2000, Nancy received her certification from The Association of Clinical Research Professionals (ACRP). Nancy has conducted more than 70 clinical trials and has supervised many GI research coordinators. In addition to her clinical trial duties, Nancy is also currently working with the department of family and community medicine's ACCION program (Against Colon Cancer In Our Communities) which is funded by CPRIT.
To make an appointment please call:
IM Clinic: 915-215-5200