Dear Patient,

Face masks are strongly encouraged but not required in all our locations. Gastro Center of Maryland is constantly working to ensure our patients have access to the care and resources they need in the safest possible setting. Our top priority is your health and safety.

To schedule please call 410-290-6677. As always, please contact us with any questions or concerns.


Doctors and Staff of Gastro Center of Maryland

Gastro Center of Maryland

Gastroenterologists located in Annapolis, MD, Columbia, MD, Riverdale, MD, & Olney, MD

Gastro Center of Maryland, with locations in Annapolis, Columbia, Olney, and Riverdale Maryland, is a medical facility that offers treatment for a variety of gastrointestinal and liver disorders:

  • Management of a complete range of Gastrointestinal, Liver and Pancreatic disorders, including Acid reflux/GERD, Stomach ulcers, Celiac disease, Irritable bowel syndrome, Colitis & Crohn’s Disease, Liver disease, Hemorrhoids and Constipation, Rectal bleeding etc.
  • Onsite Ambulatory Surgery Centers with State of the Art HD equipment, GIQuiC participation, and with accreditation and Gold Seal of Approval® from The Joint Commission.
  • Innovative and cutting edge Diagnostics and Medical Treatment- including Bravo pH Testing, SmartPill Motility testing, PillCam SB Capsule Endoscopy, Breath testing, STRETTA anti-reflux procedure, RESHAPE intragastric balloon procedure for weight loss and more.
  • IBD Infusion Center for Biologic (Remicade, Entyvio, Stelara) and Injectafer infusions.
  • Clinical Trials Center with emerging technology and therapeutics.

These are only a few of the many gastrointestinal conditions treated on a regular basis. Patients are offered individualized treatment plans based on state-of-the-art diagnostic tools and techniques that provide them with accurate and complete information. The professional staff at the facility have many years of experience to provide their patients with the most innovative and advanced treatments possible. The Providers focus on a comprehensive and Integrative treatment plan.

Gastro Center of Maryland is currently welcoming new patients, call or book an appointment online today!

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  • Rudy Rai, MD



    He is a Board-Certified Gastroenterologist & Hepatologist, with over 22 years of experience. He completed his Gastroenterology & Hepatology Fellowship at Johns Hopkins University in 1996 and completed an additional year of Advanced Fellowship at Johns Hopkins University.

    Dr Rai presents regularly at national and regional meetings and has received many awards including Excellence in Clinical Research Award from the American College of Gastroenterology, Passano Clinician Scientist Award from Johns Hopkins University, Industry Research Scholar Award & Astra-Merck Award from the American Digestive Health Foundation, among others. He has published dozens of scholarly articles in peer reviewed journals and authored many chapters for medical textbooks. He has performed over 100,000 procedures in this field and pioneered new and innovative medical techniques.

  • Eduardo Castillo, MD

    Eduardo Castillo, MD, is a board-certified physician, with specialties in both gastroenterology and hepatology. Dr. Castillo is committed to treating his patients with an exemplary level of care in a family atmosphere and is proud to offer his skills at the Gastro Center of Maryland located in Columbia and Olney, Maryland.

    Originally from Lima, Peru, Dr. Castillo received his medical degree from Lima’s prestigious Universidad Peruana Cayetano Heredia. He then traveled to Detroit, Michigan, for an internship, residency, and fellowship at the Henry Ford Hospital, where he served as chief medical resident of internal medicine and chief fellow for gastroenterology.

    Dr. Castillo has conducted a wide range of research on digestive issues, as well as liver cancer, cirrhosis, microscopic colitis, and peptic ulcer disease. In addition to being widely published, Dr. Castillo has presented his findings at national medical conferences. He’s also a member of the American Medical Association, the American Gastroenterological Association, and the American College of Gastroenterology, and is board-certified in internal medicine, gastroenterology, and hepatology.

    Dr. Castillo has a special interest in treating and preventing colon cancer, as well as treating hepatitis C, GERD, inflammatory bowel disease, and clostridium difficile infection.

  • Pia Prakash, MD

    Pia Prakash, MD, is a leading physician at the Gastro Center of Maryland in Columbia and Olney, Maryland. She is board certified in both gastroenterology and hepatology and is passionate about offering her patients personalized, compassionate care that meets their treatment goals.

    Dr. Prakash studied medicine at George Washington University School of Medicine in Washington D.C. After graduating, she completed a residency in internal medicine and a fellowship in gastroenterology, both at George Washington University. Dr. Prakash has also participated in a number of research studies, primarily focusing on colon cancer, inflammatory bowel disease (IBD), women’s health, and the impacts of celiac disease.

    Now at the Gastro Center of Maryland, Dr. Prakash treats a wide variety of conditions, including acid reflux, Crohn’s disease and ulcerative colitis, irritable bowel syndrome (IBS), celiac disease, colon cancer, hemorrhoids, and constipation. She also frequently treats acute and chronic liver disease. Dr. Prakash specializes in the use of capsule endoscopy in diagnosis, also known as PillCam®.

  • Farzin Rashti, MD, FACP

    Farzin Rashti, M.D., FACP is Board Certified in Gastroenterology & Hepatology and Internal Medicine and is dedicated to offering his patients superior personalized care in a respectful and supportive environment. Dr. Rashti works toward developing a partnership with his patients and forms a unique connection, which allows for a more individualized and targeted treatment plan.

    Dr. Rashti received his medical degree from the Howard University College of Medicine. He completed an internship year at the Los Angeles County University of Southern California Medical Center and completed his Internal Medicine residency and Gastroenterology and Hepatology Fellowship at Medstar Georgetown University Hospital/Washington Hospital Center in Washington, DC.

    Dr. Rashti has authored numerous scholarly articles and book chapters and has presented his research at national gastroenterology medical conferences. He has helped design and establish protocols for Fecal Microbiota Transplantation for the treatment of recurrent Clostridium Difficile infections. He is a Fellow of the American College of Physicians and is a member of the American Medical Association, American Gastroenterological Association, and American College of Gastroenterology.

    He treats patients with a wide variety of gastrointestinal disorders including Crohn’s Disease and Ulcerative Colitis (Inflammatory Bowel Disease), acid reflux and GERD, Irritable Bowel Syndrome, constipation, liver disease, biliopancreatic disorders, Celiac Disease, and Clostridium Difficile infections, in addition to many other ailments. Dr. Rashti specializes in performing advanced endoscopic procedures including Endoscopic Retrograde CholangioPancreatography (ERCP), Single Balloon Enteroscopy, Transoral Incisionless Fundoplication (TIF), Overstitch (endoscopic suturing), and the removal of advanced lesions.

  • Josh Rosenbloom, DO

    Josh Rosenbloom, DO, is a board-certified physician, gastroenterologist, and hepatologist at the Gastro Center of Maryland in Columbia and Olney, Maryland. He is committed to providing his patients with the best possible personalized care in a calming and professional environment.

    Dr. Rosenbloom received his medical degree from Des Moines University. After graduating, he continued his medical education at the St. John Providence health system through Michigan State University, completing a residency in internal medicine and a fellowship in gastroenterology. He also participated in research on nutrition, weight loss, hepatitis C, and improving colonoscopy preparation. Dr. Rosenbloom specializes in offering colorectal cancer screenings, weight loss assistance, pain management, and nutrition.

    Now treating patients at the Gastro Center of Maryland, Dr. Rosenbloom is experienced in treating a wide array of gastrointestinal, liver, and pancreatic diseases. He most frequently treats acid reflux and GERD, irritable bowel syndrome (IBS), ulcerative colitis, Crohn’s disease, constipation, liver disease, celiac disease, among others.

  • Dabo Xu, MD

    Dabo Xu, MD, is a board-certified physician in gastroenterology, hepatology, and internal medicine at the Gastro Center of Maryland, with locations in Columbia, Olney, and Annapolis, Maryland. Dr. Xu treats a wide variety of conditions at the practice, including gastroesophageal reflux disease (GERD), ulcerative colitis and Crohn’s disease, irritable bowel syndrome (IBS), celiac disease, colon cancer, liver disease, and other gastrointestinal conditions. 

    Dr. Xu completed his medical residency at St. Agnes Hospital, as well as a gastroenterology fellowship at the University of Michigan. He has conducted clinical and translational research on several topics, such as GERD, intestinal inflammation, liver diseases and cancers, and gastrointestinal pharmacology. His works were published in the most prestigious gastroenterology journals and presented at national and international medical conferences.

    He has more than 20 years of clinical experience in gastroenterology and hepatology. Dr. Xu has a special interest in preventive care, often working alongside patients to prevent disease and improve their quality of life through precise and effective personalized treatments.

    With a passion and dedication to patient experiences, Dr. Xu believes it’s important to build relationships with those in his care and enjoys helping patients find better health and wellness.

  • Dhruv Lowe, MD


    Bio coming soon!

  • Emily Ohland, PA-C


    Emily Ohland is a board-certified Physician Assistant. Originally from New Jersey, she completed her bachelor's degree at The College of New Jersey in 2011. She went on to earn a Master's in Physician Assistant Studies from DeSales University in 2013. Emily worked in emergency medicine at St. Agnes Hospital in Baltimore prior to joining the Gastro Center of Maryland in 2017. Emily treats a wide range of acute and chronic diseases with compassion and a focus on patient-centered care.

    She lives in Baltimore County with her husband and daughter. She enjoys traveling, hiking, and gardening.

  • Colleen Abell, CRNP

    Colleen Abell is a board-certified Family Nurse Practitioner. She graduated with a Master of Science in Nursing from Georgetown University in 2006. She has practiced as a nurse practitioner for the past sixteen years. Ms. Abell's experience includes working in a family medical clinic, but she spent most of her career providing care for patients recovering from Bariatric and GI surgical/oncology procedures. Prior to becoming a nurse practitioner, Ms. Abell worked as a Registered Nurse in cardiology and emergency medicine.

    Colleen joined the Gastro Center of Maryland in 2021 after relocating from the NY/NJ area. She is dedicated to being a great provider and advocate for her patients. Outside of work, Ms. Abell enjoys spending time with her husband and three boys.

  • Monica Lovins, CRNP

    Mrs. Monica Lovins, is a Certified Adult Nurse Practitioner who has been in health care for the last 40 years, advancing her career as a registered nurse in the ICU, Educator in the ICU as well as teaching at Catholic University of America while attaining her master's in science with a GPA of 3.89, from Felician University, Lodi, New Jersey. She has received multiple nursing award to include excellence and expertise in multiple nursing modalities.

    Monica joined Gastro Center of Maryland in 2017 after many years at John's Hospital Bayview in the Department of Surgery, Bariatric Department. Her mission to treat all gastrointestinal diseases and facilitate, best outcomes for patients who suffer from chronic gastrointestinal diseases.

    When off Monica enjoys quilting as well as spending time with family and friends.

  • Hannah Clevenger, CRNP

    A native of Pasadena, Maryland, Hannah received her Bachelor of Science in Nursing from Stevenson University. Upon graduation, she worked as a Registered Nurse at The R Adams Cowley Shock Trauma Center in Baltimore. She then went on to obtain her Master of Science in Nursing in Family Nurse Practitioner from George Washington University. Hannah has also worked as a Clinical Supervisor for nursing students in their final semester at Stevenson University. 

    Serving the communities of Annapolis, Columbia, and Olney, Hannah is a board-certified Family Nurse Practitioner. She is passionate about reducing health disparities and providing preventative care. She takes pride in her ability to listen to her patients in order to provide individualized care. 

  • Adrienne Duncan, PA-C

    A Maryland native and graduate of the Physician Assistant Program at Marywood University, Adrienne Duncan completed much of her training at The George Washington University in DC. She graduated with first-place honors in clinical excellence and is currently a member of the AAPA and MAPA organizations.

    Prior to joining Gastro Center of Maryland, Mrs. Duncan served our community for 15 years in the emergency department at The George Washington University and Shady Grove Medical Center. She brings with her a love of people and a wealth of knowledge in both acute and chronic illness. Her focus is comprised of empowering patients with education and preventative medicine.

    Outside of the office, she enjoys spending time with her husband and three children hiking, skiing, traveling and celebrating holidays with family.

  • Kirsten Parks, CRNP

    Certified Nurse Practitioner located in Annapolis and Riverdale

    Bio Coming Soon

Major Insurance Providers Accepted

Gastro Center of Maryland currently accepts most major insurance plans, including private insurance plans, federally sponsored plans, and covered Maryland plans, to provide accessible and affordable healthcare.

If you have any questions please contact our office, we will be happy to help!

View Accepted Insurance Plans

Allied Benefit Systems
Bankers Life and Casualty Company
Blue Cross Blue Shield
Harvard Pilgrim Health Care
Maryland Physicians Care
Mutual of Omaha


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