Physicians

Flint Gastroenterology Associates


Michael J. Neumann, D.O., F.A.C.O.I.

Dr. Neumann received his Bachelor of Science degree from the University of MIchigan in 1984 and proceeded to Michigan State University College of Osteopathic Medicine where he received his D.O. degree in 1988. His Internship, Internal Medicine training, and Gastroenterology fellowship were completed at Flint Osteopathic Hospital in 1993. However, during that time he also trained with world renowned faculty in Pediatric Gastroenterology, Hepatology/Liver Transplantation, and Esophageal Disease across the United States and in England.

Dr. Neumann is the senior partner at Flint Gastroenterology and treats all adult gastrointestinal (GI) disorders. Furthermore, he is a clinical faculty member and former program director of the Gastroenterology fellowship at Genesys Regional Medical Center who instructs osteopathic/allopathic students, interns, and residents.

Dr. Neumann is board certified in both Internal Medicine and Gastroenterology and is a member of the American Osteopathic Association (AOA), American College of Osteopathic Internists (ACOI), American College of Gastroenterology (ACG), and American Society of Gastrointestinal Endoscopy (ASGE). He is an Associate Clinical Professor at Michigan State University College of Osteopathic Medicine and has lectured at statewide and national medical conferences with research trial experience yielding international journal publication.

In addition to office consultation and follow-up appointments at Flint Gastroenterology Associates, Dr. Neumann provides in/outpatient services at Genesys and outpatient services at Health Park Endoscopy as well as McLaren-Flint Surgery & Endoscopy Center.


John M. Macksood, D.O., F.A.C.O.I.

Dr. Macksood received his Bachelor of Science from the University of Michigan in 1989 and proceeded to Michigan State University College of Osteopathic Medicine where he received his D.O. degree in 1993. His Internship, Internal Medicine training, and Gastroenterology fellowship were completed at Flint Osteopathic Hospital and Genesys Regional Medical Center in 1998. However, during that time, he also trained with world renowned faculty in Hepatology/Liver Transplantation and Inflammatory Bowel Disease (IBD) across the United States.

Dr. Macksood treats all adult gastrointestinal (GI) disorders. In addition, he is a clinical faculty member for the Gastroenterology fellowship at Genesys and instructs osteopathic/allopathic students, interns, and residents.  Furthermore, he is the chairman of the Department of Gastroenterology at Genesys.

Dr. Macksood is board certified in both Internal Medicine and Gastroenterology and is a member of the American Osteopathic Association (AOA), Michigan Osteopathic Association (MOA), American College of Osteopathic Internists (ACOI), American College of Gastroenterology (ACG), American Gastroenterology Association (AGA), American Society of Gastrointestinal Endoscopy (ASGE), and Genesee County Medical Society. He is an Associate Clinical Professor at Michigan State University College of Osteopathic Medicine with lectures at statewide medical conferences and research trial experience yielding international journal publication.

In addition to office consultation and follow-up appointments at Flint Gastroenterology Associates, Dr. Macksood provides in/outpatient services at Genesys and outpatient services at Health Park Endoscopy as well as McLaren-Flint Surgery & Endoscopy Center.


Derek N. Korte, D.O., F.A.C.O.I.

Dr. Korte received his Bachelor of Science degree from Truman State University in 1993 and proceeded to Kirksville College of Osteopathic Medicine where he received his D.O. degree in 1999. His Internship, Internal Medicine training, and Gastroenterology fellowship were completed at Genesys Regional Medical Center in 2005. However, during that time he also trained with world renowned faculty in Hepatology/Liver Transplantation and Inflammatory Bowel Disease (IBD) across the United States.

Dr. Korte treats all adult gastrointestinal (GI) disorders. In addition, he is a clinical faculty member for the Gastroenterology fellowship at Genesys and instructs osteopathic/allopathic students, interns, and residents. Furthermore, he is a member of the Nutrition committee and Clinical Competency Committee at Genesys.

Dr. Korte is board certified in both Internal Medicine and Gastroenterology and is a member of the American Osteopathic Association (AOA), Michigan Osteopathic Association (MOA), American College of Osteopathic Internists (ACOI), American College of Gastroenterology (ACG), and American Society of Gastrointestinal Endoscopy (ASGE). He is an Associate Clinical Professor at Michigan State University College of Osteopathic Medicine and has lectured and presented his research at statewide conferences with research trial experience yielding international journal publication.

In addition to office consultation and follow-up appointments at Flint Gastroenterology Associates, Dr. Korte provides in/outpatient services at Genesys and outpatient services at Health Park Endoscopy as well as McLaren-Flint Surgery & Endoscopy Center. Dr. Miller graduated Cum Laude with a Bachelor of Science degree from Michigan State University in 1995 and proceeded to Michigan State College of Osteopathic Medicine where he received his D.O. degree in 2000. His Internship, Internal Medicine training, and Gastroenterology fellowship were completed at Genesys Regional Medical Center in 2006. However, during that time he also trained with world renowned faculty in Hepatology/Liver Transplantation and Inflammatory Bowel Disease (IBD) across the United States.


Justin R. Miller, D.O., F.A.C.O.I.

Dr. Miller graduated Cum Laude with a Bachelor of Science degree from Michigan State University in 1995 and proceeded to Michigan State University College of Osteopathic Medicine where he received his D.O. degree in 2000. He completed his Internal Medicine residency in 2003 at Genesys Regional Medical Center (GRMC) and his Gastroenterology fellowship in 2006 at the same institution. He received the honor of being named Resident of the Year during his residency. During his fellowship he also trained with world renowned faculty in Hepatology/Liver transplantation as well as Inflammatory Bowel Disease (IBD)

In addition to his work as the Program Director for the Gastroenterology fellowship at GRMC, he is also the Gastroenterology Education Coordinator for the Internal Medicine Residency at GRMC. He serves on several hospital committees including the Department of Medicine Quality Oversight Committee. He is also a member of the Gastroenterology subsection of the Board Certification Exam Committee of the AOA.

Dr. Miller is board certified in Gastroenterology and is a member of the American College of Gastroenterology, American Gastroenterology Association, American Society of Gastrointestinal Endoscopy, American Association for the Study of Liver Disease, American Osteopathic Association and is a fellow in the American College of Osteopathic Internists. He is an Associate Clinical Professor at Michigan State University College of Osteopathic Medicine and an Adjunct Clinical Preceptor for Kirksville College of Osteopathic Medicine.

Dr. Miller treats all adult gastrointestinal disorders. In addition to office consultation and follow-up appointments at Flint Gastroenterology Associates, Dr. Miller provides inpatient and outpatient services at GRMC and outpatient services at Healthpark Endoscopy and McLaren-Flint Surgery & Endoscopy Center.


Nathan J. Landesman, D.O., F.A.C.O.I

Dr. Landesman treats all adult gastrointestinal (GI) disorders with a special interest in GI tumors as well as pancreatobiliary disease.  In addition to his 3-year GI fellowship, he is one of only a handful in the state to complete an intensive 1-year fellowship in advanced therapeutic endoscopy in Milwaukee, WI with world-renowned faculty.  He performed the first Endoscopic Ultrasound at Genesys Regional Medical Center and is the only fellowship-trained advanced endoscopist in the area.  In addition, he is a key clinical faculty member for the Gastroenterology fellowship at Genesys and instructs osteopathic/allopathic students, interns, and residents.

Dr. Landesman is board certified in both Internal Medicine and Gastroenterology and is a member of the American Osteopathic Association (AOA), Michigan Osteopathic Association (MOA), American College of Osteopathic Internists (ACOI), American College of Gastroenterology (ACG), and American Society of Gastrointestinal Endoscopy (ASGE).  In addition, he received multiple awards throughout his training for leadership, teaching, and quality patient care with lecture/poster presentations at medical conferences throughout the United States. 

Dr. Landesman provides thorough, compassionate care with excellent communication skills and prides himself on a team approach to achieve unsurpassed outcomes.

In addition to office consultation and follow-up appointments at Flint Gastroenterology Associates, Dr. Landesman provides in/outpatient services at Genesys and outpatient services at Health Park Endoscopy as well as McLaren-Flint Surgery & Endoscopy Center. 


Mark J. Minaudo, D.O.

Dr. Minaudo received his Bachelor of Science degree from the University of Michigan in 2000 and proceeded to Michigan State College of Osteopathic Medicine where he received his D.O. degree in 2006. His Internship, Internal Medicine training, and Gastroenterology fellowship were completed at Genesys Regional Medical Center in 2012. However, during that time he also trained with world renowned faculty in Hepatology/Liver Transplantation and Inflammatory Bowel Disease (IBD) across the United States.

Dr. Minaudo treats all adult gastrointestinal (GI) disorders. In addition, he is a key clinical faculty member for the Gastroenterology fellowship at Genesys who instructs osteopathic/allopathic students, interns, and residents.  Furthermore, he a member of the Clinical Competency Committee at Genesys.

Dr. Minaudo is board certified in both Internal Medicine and Gastroenterology and is a member of the American Osteopathic Association (AOA), Michigan Osteopathic Association (MOA), American College of Osteopathic Internists (ACOI), American College of Gastroenterology (ACG), American Gastroenterology Association (AGA), and American Society of Gastrointestinal Endoscopy (ASGE). In addition, he received recognition throughout his training for leadership, teaching, and quality patient care. He is an Associate Clinical Professor at Michigan State University College of Osteopathic Medicine and has presented his research as well as lectured at statewide medical conferences.

In addition to office consultation and follow-up appointments at Flint Gastroenterology Associates, Dr. Minaudo provides in/outpatient services at Genesys and outpatient services at Health Park Endoscopy as well as McLaren-Flint Surgery & Endoscopy Center.


Derek W. Thigpin, D.O.

Dr. Thigpin received his Bachelor of Science degree from the University of Oklahoma in 2004 and proceeded to Oklahoma State University College of Osteopathic Medicine where he received his D.O. degree in 2008. His Internship, Internal Medicine residency, and Gastroenterology fellowship were completed at Genesys Regional Medical Center in 2014. However, during that time he also trained with world renowned faculty in Hepatology/Liver Transplantation, Esophageal Disease, Functional Bowel Disorders, and Inflammatory Bowel Disease (IBD) across the United States.

Dr. Thigpin treats all adult gastrointestinal (GI) disorders. In addition, he is a key clinical faculty member for the Gastroenterology fellowship at Genesys Regional Medical Center and instructs osteopathic/allopathic students, interns, and residents.  Furthermore, he is a member of the Clinical Competency Committee at Genesys.

Dr. Thigpin is board certified in both Internal Medicine and Gastroenterology and is a member of the American Osteopathic Association (AOA), Michigan Osteopathic Association (MOA), American College of Osteopathic Internists (ACOI), American College of Gastroenterology (ACG), and American Society of Gastrointestinal Endoscopy (ASGE). In addition, he is an Associate Clinical Professor at Michigan State University College of Osteopathic Medicine with lectures and research/poster presentations at statewide and international medical conferences.

In addition to office consultation and follow-up appointments at Flint Gastroenterology Associates, Dr. Thigpin provides in/outpatient services at Genesys and outpatient services at Health Park Endoscopy as well as McLaren-Flint Surgery & Endoscopy Center.

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