George W. Marek, III, M.D., Ph.D.

George William Marek, III, M.D., Ph.D., is a Gastroenterologist in the consultative group at Mayo Clinic. Dr. Marek practices Gastroenterology in the Consultative Interest Group at Mayo Clinic in Rochester. He practices general Gastroenterology and provides outpatient consultation services and performs general and complex endoscopic procedures and works as a clinical educator and scientist.

He is a native of Florida originally and completed his MD, PhD training and internal medicine residency training before completing Gastroenterology training at Mayo Clinic in Rochester.

He has research and clinical interests in Alpha-1 antitrypsin deficiency. He sees patients with a wide variety of gastrointestinal problems and seeks to incorporate cutting edge diagnostics with wholistic patient-centered approaches to serious and complex gastrointestinal symptoms.

Areas of expertise

Dr. Marek provides comprehensive evaluation and care for complex gastrointestinal disorders and performs advanced endoscopic procedures, including:

• Alpha-1 antitrypsin deficiency: Diagnosis and management of liver and digestive complications associated with this condition.
• Celiac disease and related enteropathies: Personalized strategies for diagnosis, treatment, and symptom control.
• Complex gastrointestinal concerns: Evaluation of challenging and significant GI complaints requiring multidisciplinary care.
• Premalignant gastrointestinal polyps and growths: Endoscopic removal and long-term surveillance.
• Colonoscopy: Diagnostic and therapeutic procedures, including polyp detection and removal.
• Upper endoscopy (EGD): Evaluation and treatment of esophageal, gastric, and duodenal conditions.
• Pouchoscopy and ileoscopy: Specialized assessment of intestinal pouches and lower small bowel.
• Push enteroscopy and feeding tube placement: Procedures to address small bowel issues and nutritional support needs.

Research and professional highlights

Dr. Marek serves as an Assistant Professor of Medicine at Mayo Clinic College of Medicine and Science. His research focuses on Alpha-1 antitrypsin deficiency (AATD) and its impact on liver disease, as well as metabolic dysfunction-associated steatohepatitis (MASH). He investigates genetic and clinical predictors of disease progression and explores innovative strategies for precision medicine using integrated genomic and clinical data. He has authored numerous publications on liver disease mechanisms, advanced endoscopic therapies, and complex digestive disorders.

Dr. Marek is board certified in Internal Medicine by the American Board of Internal Medicine and board certified in Gastroenterology. He completed fellowship training in Gastroenterology at Mayo Clinic in Rochester, Minnesota. He is actively engaged in educating trainees and contributing to multidisciplinary care models that enhance outcomes for individuals with rare and advanced GI diseases.

Personal note

Dr. Marek values personalized, evidence-based care, stating, “For each patient I try to clearly understand their diagnosis and develop a personal treatment option using evidence-based medical and procedural approaches — and natural and integrative approaches when they are appropriate.” Outside of his clinical and research work, he enjoys gardening, woodworking, and spending time outdoors.