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Department Pediatric Gastroenterology, Hepatology, and Nutrition
Primary Location Cleveland Clinic Main Campus
Type of Doctor Children & Adolescents Only
Languages English
Surgeon No
Locations Specialties & Treatments

Treatment & Services

  • Care of Liver Related Metabolic Problems
  • Care of Liver Transplant Patients
  • Center for Pediatric Gastroenterology
  • Liver Biopsy
  • Liver Transplant
  • Pediatric Liver Transplant
View all 6 Treatment & Services +

Specialty in Diseases & Conditions

  • Achalasia
  • Acute Liver Failure
  • Biliary Atresia
  • Cirrhosis
  • Diseases of the Liver, Biliary Tract and Pancreas
  • Gallbladder Disease
  • Gallstones
  • Hepatitis B
  • Hepatitis C
  • Liver Disease
  • Metabolic Diseases
  • Mitochondrial Disease
  • Non-Alcoholic Fatty Liver Disease
  • Primary Sclerosing Cholangitis
View all 14 Specialties +


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Biography Education & Professional Highlights

Education & Professional Highlights


Education & Fellowships

Fellowship - Cincinnati Children's Hospital
Pediatric Gastroenterology
Cincinnatii, OH

Residency - University of Utah Medical Center
Salt Lake City, UT

Graduate School - Washington University
Ph.D. in Molecular Biology
St. Louis, MO

Medical Education - Washington University in St. Louis
MD/PhD combined program
St. Louis,

Undergraduate - Washington University in St. Louis
St. Louis, MO


  • Pediatrics - Pediatric Transplant Hepatology
  • Pediatrics - Pediatric Gastroenterology
Research & Publications

Research & Publications

See publications for Mike Leonis, MD, PhD.

(Disclaimer: This search is powered by PubMed, a service of the U.S. National Library of Medicine. PubMed is a third-party website with no affiliation with Cleveland Clinic.)

Industry Relationships

Industry Relationships

Cleveland Clinic physicians and scientists may collaborate with the pharmaceutical or medical device industries to help develop medical breakthroughs or provide medical expertise or education. Cleveland Clinic strives to make scientific advances that will benefit patient care and support outside relationships that promise public benefit. In order for the discoveries of Cleveland Clinic physicians' and scientists' laboratories and investigations to benefit the public, these discoveries must be commercialized in partnership with industry. As experts in their fields, Cleveland Clinic physicians and scientists are often sought after by industry to consult, provide expertise and education.

To assure professional and commercial integrity in such matters, Cleveland Clinic maintains a program that reviews these collaborations and, when appropriate, puts measures in place to minimize bias that may result from ties to industry. Cleveland Clinic publicly discloses the names of companies when (i) its physicians/scientists receive $5,000 or more per year (or, in rare cases, equity or stock options) for speaking and consulting, (ii) its physicians/scientists serve as a fiduciary, (iii) its physicians/scientists receive or have the right to receive royalties or (iv) its physicians/ scientists hold any equity interest for the physician's/scientist's role as inventor, discoverer, developer, founder or consultant.* In publicly disclosing this information, Cleveland Clinic tries to provide information as accurately as possible about its physicians' and scientists' connections with industry.

As of 4/20/2023, Dr. Leonis has reported no financial relationship with industry that is applicable to this listing. In general, patients should feel free to contact their doctor about any of the relationships and how the relationships are overseen by Cleveland Clinic. To learn more about Cleveland Clinic's policies on collaborations with industry and innovation management, go to our Integrity in Innovation page.

Public Health Service-Reportable Financial Conflicts of Interest. Cleveland Clinic scientists and physicians engage in basic, translational and clinical research activities, working to solve health problems, enhance patient care and improve quality of life for patients. Interactions with industry are essential to bringing the researchers' discoveries to the public, but can present the potential for conflicts of interest related to their research activities. Click here to view a listing of instances where Cleveland Clinic has identified a Public Health Service (PHS)-Reportable Financial Conflict of Interest and has put measures in place to ensure that, to the extent possible, the design, conduct and reporting of the research is free from bias.

* Cleveland Clinic physicians and scientists subscribe to the guidance presented in the PhRMA Code on Interactions with Healthcare Professionals and the AdvaMed Code of Ethics on Interactions with Health Care Professionals. As such, gifts of substantial value are generally prohibited.

Patient Satisfaction Reviews

32 Patient Satisfaction Reviews

The Patient Satisfaction Rating is an average of all responses to the care provider related questions shown below from our nationally-recognized Press Ganey Patient Satisfaction Survey. Patients that are treated in outpatient or hospital environments may receive different surveys, and the volume of responses will vary by question.

Responses are measured on a scale of 1 to 5 with 5 being the best score.

The comments are submitted by patients and reflect their views and opinions. The comments are not endorsed by and do not necessarily reflect the views of Cleveland Clinic.

Overall Star Ratings
4.5 out of 5
Explains 4.5
Courtesy, Respect & Concern 4.5
Patient Rating of Doctor 4.4

6 Patient Comments

Reviewed on Apr 22, 2024

Overall experience is great! And the doctors, nurses, and other staff are very polite. Thank you!

Reviewed on Dec 13, 2023

Doctor was above and beyond! I absolutely loved the person he is explaining everything to my child and I! No questions went unanswered!

Reviewed on Dec 13, 2023

Dr. Was incredible! He was extremely warm and calm. He relaxed me and my daughter! He handed her with care and me as well! Any questions I had he answered. Any concerns he put me at ease. First doctor that made me feel super trusting with my child! His kind words were much needed! I can tell he's a great man in and outside the field! 10/10!

Reviewed on Aug 4, 2023

Unfortunately due to lack of respect and proper recommendations, as well as discussion about a plan regarding my son's care. We will not be returning to see provider.

Reviewed on Jul 14, 2023

Dr. Leonis was very compassionate and thorough. He was so great with my son, and spent time asking questions to try to figure out the problem and possible solutions.

Reviewed on Jun 13, 2023

Provider was thorough, took a tremendous amount of time listening as well as explained the next steps in a way that was easy to process on the parent end. That added piece of attentiveness and compassion goes a long way in reassuring a parent when something is happening with their child.

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