We are currently experincing technical difficulties and you may experience longer wait time than usual.
If it is a life threatening emergency, please dial 911. Otherwise please send an email to officemanager@gastromaryland.com.
We appreciate your patience and understanding! 

Dear Patient,

During this challenging time, 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. Gastro Center of Maryland is OPEN and committed to providing you with ongoing care.

For the continued safety of our patients and staff we are offering ALL essential services:

  1. Tele-health appointments: Video (Zoom/Facetime) or Teleconference Calls are now available to all patients!
  2. Physical In-Office Appointments:

         a. Urgent in-office appointments for New and Existing patients

         b. Urgent Endoscopy / Colonoscopy procedures

         c. Biologic/Medication Infusions

         d. Other Laboratory or Diagnostic Testing is also available

To schedule please call 410-290-6677 


  • If you were exposed to COVID -19 and are up to date on vaccinations, you do not need to stay home unless you develop symptoms. If you develop symptoms, please call us to request a telehealth visit or reschedule your endoscopy appointment. 
  • Clinic patients- please limit family members coming into the clinic to only those needed for the appointment.
  • Endoscopy and Infusion patients- if someone is driving you to and from your appointment please be aware that they will be asked to socially distance outside the office during your treatment/procedure.
  • We require all patients coming into the office to wear face coverings to keep you and our staff safe.

As the Coronavirus situation evolves, our policies and recommendations will as well. Thank you for your cooperation and patience during this challenging time. As always, please contact us with any questions or concerns.


Doctors and Staff of Gastro Center of Maryland

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Gastro Center of Maryland

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

Dr. Rudy Rai Welcomes You to Our Practice!

Dr. Rudy Rai Welcomes You to Our Practice!

Learn More About Our Providers & Staff

  • Dr. Rai was awarded the “TOP DOC” in Gastroenterology award by Baltimore Magazine for 2016.

    Dr. Rai is a Board Certified Gastroenterologist & Hepatologist, with over 22 years of experience in this field. He is the Medical Director of Gastro Center of Maryland & Cascades Endoscopy Center and has served on the Medical Faculty at Johns Hopkins University School of Medicine for many years, starting in 1997. He has been in many leadership positions in the Johns Hopkins Division of Gastroenterology & Hepatology, including as the Medical Director, Adult Liver Transplantation and Director, Clinical Effectiveness. He completed his Gastroenterology & Hepatology Fellowship at Johns Hopkins University in 1996 and completed an additional year of Advanced Fellowship at Johns Hopkins University in Transplant Hepatology and Biliary Disorders.

    Dr. Rai is considered a national thought leader and expert in the field of Gastroenterology and Liver disease and presents regularly at national and regional meetings. He 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 50,000 procedures in this field and pioneered new and innovative medical techniques.

  • 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, 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®.

  • Josh Rosenbloom, MD, 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.

  • Bio Coming Soon!

  • Bio Coming Soon!

  • Elizabeth graduated nursing school in 1996, and most recently in 2013, she graduated with highest honors from The University of Texas Arlington with a BSN, Bachelor of Science in Nursing. She has worked as a registered nurse in various specialties in the area for the past twenty years, and has been with our organization since 2011. Her goal is to provide our clients with the best endoscopy experience! She is a natural leader and has a strong nursing staff to prove it. Elizabeth is interested in effectively improving individual’s healthy behaviors, and to help educate positive lifestyle changes to promote gastrointestinal health.

Major Insurance Providers Accepted

At Gastro Center of Maryland, we accept most major insurance plans. Here is a short-list of just some of the most popular plans we accept.

Click HERE for the Full Insurance List, or contact our office if you do not see your insurance provider listed.

Contact us!

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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