Our Providers

Gastroenterologists

Scott A. Plaehn, DO, FACOI
Scott Plaehn, DO, FACOI

Dr. Plaehn is a medical graduate from the Chicago College of Osteopathic Medicine in Illinois.  He performed his Internship and Residency at Metropolitan Hospital in Grand Rapids, Michigan an affiliate of Michigan State University.  He then went on to Botsford General Hospital in Farmington Hills, Michigan where he completed his Fellowship in Gastroenterology.  Dr. Plaehn is board certified in both Internal Medicine and Gastroenterology.  He has been practicing in the Lansing area since 1996.

Albert B. Ross, MD
Albert Ross, MD

Dr. Ross received his medical degree from Washington University in St. Louis, Missouri where he graduated with honors.  His Internship and Residency were performed at the University of Chicago Hospital and his Fellowship was completed at Froedtert Memorial Lutheran Hospital in Milwaukee, Wisconsin.  He is board certified in both Internal Medicine and Gastroenterology.  Dr. Ross has been practicing in the Lansing area since 1995.

Dorian T. Jones, MD
Dorian Jones, MD

Dr. Dorian Jones was born in Detroit, Michigan, and grew up in Romulus and Canton, Michigan. From an early age, he had a passion for science and helping others. He graduated from Plymouth Salem High School with distinction.  He received a Bachelor of Arts in Chemistry from Kalamazoo College in Kalamazoo, Michigan.  He also completed a minor in Biology with concentrations in molecular biology and biochemistry.  His senior thesis was in synthetic organic chemistry.  During his time at Kalamazoo College, he studied abroad in Madrid, Spain, and served on many committees.  Afterward, he received his Doctor of Medicine (M.D.) from Tufts University School of Medicine in Boston, Massachusetts.  Next, he completed internal medicine training at the Cleveland Clinic Foundation in Cleveland, Ohio, and served an additional year as a Chief Medical Resident.  During this time, he completed training in process improvement, and participated in training in Lean and Six Sigma. He completed Gastroenterology and Hepatology Fellowship at Henry Ford Hospital in Detroit, Michigan.  During training, he researched and published in inflammatory bowel disease, process improvement, patient safety, and liver disease.  Later, he moved to Okemos with his wife and daughter, and joined the Digestive Health Institute.  Since his arrival in 2018 he has enjoyed seeing patients in Gastroenterology and Hepatology, and servicing the community.  In addition to his work in medicine and research, he enjoys sports, running, weightlifting, photography, reading, and cooking.

Jannel Lee-Allen, MD, MUP
Jannel Lee-Allen, MD
Dr. Matthew DiMagno on blue background
Tadd Hiatt, MD
Dr. Matthew DiMagno on blue background
Matthew J. DiMagno, MD, AGAF
Margaret J. Blayney, MD. MSt
Margaret Blayney MD, MSt

Physician Assistants

Jonathan Thelen, PA-C
Jonathan Thelen, PA-C

Jonathan Thelen PA-C obtained his Bachelor of Science Degree in human biology with a specialization in health promotion from Michigan State University in May 2007. He then attended Central Michigan University and graduated with a Master’s Degree and Certification in Physician Assistant Studies in July 2009. He has been with Digestive Health Institute since 2009. He also holds the position of the Mid-Level Provider Coordinator.

Andrea Koerner, RD, PA-C
Andrea Koerner, RD, PA-C

Andrea Koerner PA-C obtained her Bachelor of Science Degree in Dietetics from Central Michigan University. She then completed the University of Michigan Health System Dietetic Internship which enabled her to become a Registered Dietitian. She then attended Eastern Michigan University and graduated with a Master’s Degree and Certification in Physician Assistant Studies in July 2019. She has been with Digestive Health Institute since 2021.

Don Laird, PA-C
Don Laird, PA-C

Don Laird PA-C achieved his Bachelor of Science Degree in human biology from Michigan State University in May 2007. He continued his graduate studies at Central Michigan University and earned his Masters degree and Certification in Physician Assistant Studies in July 2009. He has been with Digestive Health Institute since 2009.

Scott Zeilstra, PA-C
Scott Zeilstra, PA-C

Scott Zeilstra PA-C achieved his Master’s Degree from Central Michigan University Physician Assisting Program and joined Digestive Health Institute after graduation in 2013. He is certified by the National Commission on Certification of Physician Assistants.

Erin Wolf, PA-C
Erin Wolf, PA-C

Erin Wolf, PA-C, earned her Bachelor of Science degree in Neuroscience and Spanish from the University of Michigan in 2016. She went on to receive her Master of Science in Physician Assistant Studies from the University of St. Francis in Indiana in 2021.

She practiced as a hospitalist PA for 5 years before joining the Digestive Health Institute team in 2026. She is certified by the National Commission on Certification of Physician Assistants (NCCPA). 

What Our Patients Are Saying

Jeanne D.
1 day ago
Clear quick communication. Pleased.
Linda S.
7 days ago
Professional staff, did not wait long, listened and provided the help I needed.
Lisa G.
1 week ago
I’ve had a great experience with DHI. They have been attentive and listen carefully. I always leave with a plan of action- I would recommend them to family and friends.
Kathy M.
1 week ago
My PA Scott did a fantastic job of going over my records with me, making the transition to a new doctor and PA so much more comfortable. Change can be difficult when you've been seeing the same doctor for years and have developed a solid relationship with your doctor and his/her assistants. I have also spent time with Amanda, who is so personable and understanding. Dr LeeAllan is also very thorough and thoughtful, and she takes the time to listen and weigh out a 'course of treatment'. I'm feeling way better about Dr. Walling's retirement!
Roberta M.
2 weeks ago
The doctor ask me questions about the history of my issue. He suggested treatment. Further tests were scheduled in a timely manner. A follow up visit will be scheduled after the test results are in. It was a very productive appointment.
Sarah P.
2 weeks ago
I saw Donald Laird. He was very prompt, thorough, informative, well- educated, and listened well to all my concerns and health history. Very happy to have been sent here, just wish it would have been years sooner like it should have been.
Stefan G.
2 weeks ago
The staff at the Digestive Health Institute | Gastroenterology is a remarkable group of people. Let’s be honest, nobody looks forward to seeing a gastroenterologist, so when the staff at a medical practice—the ENTIRE staff—is kind and helpful, patients are going to feel more comfortable being there. That is the hallmark of patient-centered care, and it’s what I experienced at the Digestive Health Institute | Gastroenterology. The intake person at the front desk was pleasant, helpful and efficient. I was struggling with my allergies and needed water, and after directing me to the water fountain, he offered me a cup. While that’s a small gesture, it demonstrated real consideration. My medical history was taken by a staff member who was engaging and friendly. I saw a medical resident who spoke with me about why I was there. I gave her some of my history, and then I saw Jannel Lee-Allen. Dr. Lee-Allen has a remarkably good bedside manner. She showed concern while at the same time being direct. Hearing things that are potentially unpleasant are sometimes best said in a direct way, and I value that. Dr. Lee-Allen was clear and concise and direct, but her clarity was infused with a sense of humor. Again, that’s putting a patient at ease. I had to schedule a procedure, and that involved spending a lot of time with the scheduler. She took the time I needed. I never felt rushed. The time it took was based not on her getting to the next patient. It was about what I needed and making sure I understood everything about preparation for an upcoming procedure. I struggled to understand some things, and I needed her to go over them several times. The scheduler, however, was reassuring, telling me she would take the time necessary. She wanted to make sure I understood what was happening. This is another example of how the Digestive Health Institute | Gastroenterology believes in patient-centered care—something they demonstrated that every step of the way.
John W. S.
2 weeks ago
always satisfied with my treatment
Leslie B.
3 weeks ago
Dr. Don is really cool ! Hes a great dr. Been coming to this place for quite a while & glad there here to help.😊
Richard W H.
4 weeks ago
Courteous, Professional, Kind Staff. Great demeanor and medical knowledge.