Mary Harris Profile Image

Medical Co-Director, The Center for Inflammatory Bowel and Colorectal Diseases


  • Gastroenterology


  • English

Areas of Interest:

  • Ulcerative Colitis, Crohn's Disease, Inflammatory Bowel Diseases, Microscopic Colitis (Lymphocytic Colitis and Collagenous Colitis), Diarrhea


  • McAuley Plaza at Mercy
  • Mercy Personal Physicians at Lutherville

Mary Harris, M.D.

Mary L. Harris, M.D., Medical Co-Director of The Center for Inflammatory Bowel and Colorectal Diseases, part of The Melissa L. Posner Institute for Digestive Health & Liver Disease at Mercy, is a recognized regional authority in greater Baltimore and the Mid-Atlantic region in the diagnosis and treatment of inflammatory bowel and colorectal diseases. She uses her advanced skills to help patients with these illnesses lead full and normal lives. Dr. Mary Harris devotes time to patients helping them understand their illness and providing education for successful self-management of the disease. Many of her patients are empowered through her help and feel more positive about controlling their illness.

Specialist in Crohn's Disease, Ulcerative Colitis and Irritable Bowel Syndrome

As a leader of The Center for Inflammatory Bowel and Colorectal Diseases, Dr. Mary Harris provides patients with advanced treatment and state-of-the-art technology to help them manage their illness. Dr. Mary Harris was instrumental in bringing Remicade Infusion, a breakthrough medical management for Crohn’s Disease and ulcerative colitis, to Mercy.

Dr. Harris is a renowned specialist in inflammatory bowel management and has written book chapters and peer reviewed manuscripts on the subject. Her skills and advanced clinical knowledge keep patients confident in her treatment and care. 

Dr. Mary Harris helps patients receive comprehensive care by working collaboratively with the specialists of The Institute for Cancer Care at Mercy, The Center for Minimally Invasive Surgery at Mercy, The Center for Interventional Pain Medicine at Mercy and the Division of Interventional Radiology. This multi-modality method of diagnosis and treatment of digestive health and liver disease and the expertise of our doctors make The Institute for Digestive Health & Liver Disease at Mercy among the best in the Mid-Atlantic region.

Dr. Harris has been named a "Top Doctor" in Gastroenterology - Inflammatory Bowel Disease by Baltimore magazine.

Authority on Inflammatory Bowel and Pregnancy

Managing inflammatory bowel disease while pregnant can be tricky, and for some patients overwhelming. Dr. Mary Harris is considered an authority on treating inflammatory bowel diseases in conjunction with pregnancy. Many patients who are considering childbirth come to Dr. Mary Harris prior to pregnancy for disease planning and management. She works with obstetricians to coordinate care and helps patients throughout the course of their pregnancy to manage their illness.

Leading Edge Research and Publication

Dr. Mary Harris has been a noted researcher on health issues in inflammatory bowel disease and her topics have covered:

  • Classification and Subtypes in Crohn’s Disease
  • Endoscopic Ultrasound
  • Therapeutic Approaches in Inflammatory Bowel Disease

She has also written numerous peer-reviewed manuscripts, book chapters and abstracts. Her work has appeared in such noteworthy publications as:

  • Digestive Diseases and Sciences
  • Gastroenterology
  • Gastrointestinal Endoscopy
  • The Lancet
Education & Fellowships
  • Fellowship – Gastroenterology, The Johns Hopkins Hospital
  • Residency – University of Virginia School of Medicine
  • Medical Degree – University of Virginia School of Medicine
Associations & Memberships
  • American College of Physicians
  • American Gastroenterologist Association
  • Crohn’s and Colitis Foundation, Member Physician Advisory Committee


Insurances Accepted

See a list of insurances accepted at Mercy. Restrictions may apply. Patients should confirm coverage with their carrier prior to appointment date.