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Mark Donowitz, M.D.

Mark Donowitz, M.D.

Headshot of Mark Donowitz
  • Director, Hopkins NIH/NIDDK Conte Core Center
  • Professor of Medicine


Anal Fistula, Celiac Disease, Celiac Sprue, Clinical Gastroenterology, Clostridium Difficile, Colitis, Constipation, Crohn's Disease, Diarrhea, Diarrheal Disease, Digestive Disorders, Gastroenterology, GI Dysplasia, Ileitis, Inflammatory Bowel Disease (IBD), Malabsorption, Microscopic Colitis, Pouchitis, Proctitis, Short Bowel Syndrome, Ulcerative Colitis more

Research Interests

Intestinal Salt Absorption and the proteins involved including their regulation; Development of drug therapy for diarrheal disorders; Use of human enteroids to understand intestinal physiology and pathophysiology more

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The Johns Hopkins Hospital

Appointment Phone: 410-933-7495
600 N. Wolfe Street
Ross Research Building Suite 925
Baltimore, MD 21287 map
Phone: 410-955-9675 | Fax: 410-955-9677


Mark Donowitz, M.D . has had a distinguished career of scientific discovery, mentorship of young researchers and advocacy for the gastroenterology specialty. Dr. Donowitz is LeBoff Professor of Medicine and Professor of Physiology, Director of the Hopkins Center for Epithelial Disorders at The Johns Hopkins University School of Medicine, and is Founding Director of the NIH/NIDDK Hopkins Conte Digestive Diseases Center for Basic and Translational Research. He was President of the American Gastroenterological Association 2006-2007. He also served as President of the Gastroenterology-Research Group. He has received the Distinguished Achievement Award and as well as the Davenport Memorial Prize from the American Physiology Society, and is a Fellow of the American Association for the Advancement of Science.

His scientific focus has been to understand regulation of intestinal Na absorption in normal digestive physiology and abnormalities that contribute to diarrheal diseases. His group was the first to recognize the mammalian Na/H exchanger gene family, to clone the epithelial isoforms, and to trace the evolutionary development of the gene family. He has examined structure/function aspects of the exchangers and identified the large, multiprotein complexes in which the epithelial NHEs function. In addition, his group identified a gene family of PDZ containing brush border proteins called the NHERF family which are scaffolding proteins which interact with NHE3 and are involved in forming the multiprotein complexes, are critical for its regulation, and take part in its association with the cytoskeleton.

He has pioneered use of human mini-intestines made from normal human subjects to advance understanding of human digestive physiology and pathophysiology especially related to host-pathogen interactions.

His clinical interests are in diagnosis and management of chronic diarrheal diseases, including short gut syndrome, inflammatory bowel diseases and celiac disease. more


  • Director, Hopkins NIH/NIDDK Conte Core Center
  • GI Division, Director of Basic Research
  • Professor of Medicine

Departments / Divisions

Centers & Institutes



  • MD; Johns Hopkins University School of Medicine (1968)

Board Certifications

  • American Board of Internal Medicine (Gastroenterology) (1975)
  • American Board of Internal Medicine (Internal Medicine) (1972)

Activities & Honors


  • AAAS
  • AAP
  • American Gastroenterogical Association
  • American Physiological Society
  • ASCI
  • Interurban Clinical Club

Professional Activities

  • President, Gastoenterology Research Group
  • President, Interurban Clinical Club
  • President , American Gastroenterological Association, 2006 - 2007

Videos & Media

Recent News Articles and Media Coverage

Mini-Intestines May Hold Promise for Patients with Diarrheal Disease, Inside Tract (Winter 2018)

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