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Andrew Overhiser

Andrew Overhiser, MD

Gastroenterology

Accepting New Patients
Need help scheduling? Call 928-773-2332

Highlights

Age Groups Seen

  • Adult 18-55
  • Older Adult >55

Languages

  • English

Gender

Male

About Andrew Overhiser

“I’m constantly looking for ways to improve my abilities and knowledge to better care for my patients and find the best possible outcomes.”   

Care Philosophy: 

Andrew Overhiser, MD, works to listen to his patients and to engage them in their options for treatment. He helps to address health concerns, assisting patients to find a plan for better health that includes addressing diet and lifestyle and other interventions, such as testing and medications, as needed. 

Medical Specialty: 

Dr. Overhiser specializes in colon cancer screenings, including colonoscopy with polyp detection and removal. His areas of focus also include inflammatory bowel disease, GERD and management of irritable bowel syndrome. 

Professional Achievements: 

Dr. Overhiser completed his medical degree and his postdoctoral training as an internal medicine resident at Indiana University School of Medicine in Indianapolis. His gastroenterology and hepatology fellowship programs were completed at the University of Kansas Medical Center in Kansas City. 

Dr. Overhiser is board-certified in gastroenterology and is a member of the American Gastroenterological Association, American Society for Gastrointestinal Endoscopy and American College of Gastroenterology.  

Pronouns

He/Him

Video

Locations

  1. Gastroenterology at Northern Arizona Healthcare

Expertise

Education

  • Fellowship: University of Kansas Medical Center (Kansas City), Gastroenterology
  • Internship & Residency: Indiana University School of Medicine (Indianapolis), Internal Medicine
  • Medical Education: Indiana University School of Medicine (Indianapolis), MD

Board Certifications

  • Gastroenterology: American Board of Internal Medicine
  • Internal Medicine: American Board of Internal Medicine

Ratings & Reviews

5 out of 5

139 ratings, 43 reviews

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

Search reviews
    5 out of 5 stars
    Reviewed on 2/17/2026

    Highly recommended. World class medicine here in Flagstaff.

    5 out of 5 stars
    Reviewed on 1/29/2026

    Very Good

    5 out of 5 stars
    Reviewed on 1/27/2026

    Dr. Overhiser is compassionate, clear in explaining my condition and all options for my treatment.

    5 out of 5 stars
    Reviewed on 1/26/2026

    Dr. Overhiser is wonderful.

    5 out of 5 stars
    Reviewed on 1/13/2026

    Dr. Overhiser is an excellent doctor. He listens and works with you to get better and solve any issues.

    5 out of 5 stars
    Reviewed on 1/13/2026

    Dr Overhiser is the best GI I've had, and best overall physician. Considers condition holistically and suggest other care/ tests that should be done to maintain health.

    5 out of 5 stars
    Reviewed on 12/23/2025

    Dr. Overhiser is the epitome of knowledge and patient care. His attitude is thoroughly warm, concerning and open to interaction and explanation of each and every step of care involved in the process of patient care. Dr. Overhiser has relaxed and restored my image of the medical professional which in turn, has enhanced our interaction as he actually cares and demonstrates his own true concern through his every explanation and resolve in caring for his patients. This a step forward for all patient care and the change necessary for removal of the negativity and aloofness practised by too many other medical professionals. Dr. Overhiser is a prime example of true professionalism, empathy and compassion, he listens, learning about ones each and every concern and worry and never hurries visit or conversation as he gets to know his patient. Thank you Dr. Overhiser for being humane!

    5 out of 5 stars
    Reviewed on 12/23/2025

    Dr Overhiser is a skilled and caring physician. One of the best doctors I've ever seen. I am extremely pleased being under his care.

    5 out of 5 stars
    Reviewed on 12/16/2025

    We love Dr Overhiser...we recommend him to everyone

    5 out of 5 stars
    Reviewed on 12/16/2025

    I recommend Dr. Overhiser regularly. He is a cut above most physicians. He takes the time to review history before the appointment and already knows my most recent tests and diagnoses when the appointment begins. He starts by asking questions and really listening. He gives space for my questions and concerns. His knowledge is vast, and he will also research anything that's new to him. I have uncommon underlying conditions that he already understood in my first appointment with him...that is unusual! I feel well-cared for by Dr. Overhiser, and really trust him. So thankful he is close enough to see!

    5 out of 5 stars
    Reviewed on 12/2/2025

    Dr O is the best! Clone him! Good luck!

    5 out of 5 stars
    Reviewed on 11/18/2025

    Excellent care.

    5 out of 5 stars
    Reviewed on 11/18/2025

    Dr. Overhiser is everything a physician should be.

    5 out of 5 stars
    Reviewed on 11/5/2025

    Dr. Overhiser is an amazing physician! He takes the time to explain what is going on with your health.

    5 out of 5 stars
    Reviewed on 10/28/2025

    Dr. Overhiser is excellent: kind and thorough. He listens and explains well. I am very pleased with my care.

    5 out of 5 stars
    Reviewed on 10/28/2025

    I was edified to hear that Dr. Overhiser researched my rare stomach condition for updates before we met. He thoroughly explained the procedure, why he is choosing certain options, and openly invited and responded to my questions.

    5 out of 5 stars
    Reviewed on 10/24/2025

    Dr Overhiser is excellent in hearing my concerns and responding to them with his expansive knowledge.

    5 out of 5 stars
    Reviewed on 10/9/2025

    Dr. Overhiser has listened, and done more for me than any other gastroenterologist including several specialist in Phoenix.

    5 out of 5 stars
    Reviewed on 9/25/2025

    Dr. Overhiser took his time to listen to my concerns and explained my care management plan in detail. He was caring and professional

    5 out of 5 stars
    Reviewed on 9/23/2025

    Dr Overhiser is one of the kindest and caring human beings I have ever met, let alone a Dr! God Bless Him.

    5 out of 5 stars
    Reviewed on 9/23/2025

    Dr. Overhiser honestly, is an outstanding physician and human being! He spoke to me with concern and recognition for any and all questions, worries, concerns and was very genuine in addressing every aspect of my illness from beginning to end. He explained to me exactly how each point of treatment would be addressed and adapted to what my own body could tolerate and how, if and when, my body rejected said treatment(s) he would continue forward researching and finding the most tolerable and helpful treatment for my special circumstances. I relaxed and felt at ease and reassured that my journey of pain and discomfort would finally be helped and taken into serious and adequate attention and concern. I am finally comfortable aware that Dr. Overhiser sees me as a human being in distress and not a number or just another messed up patient. He, not only, sees you but, shows real compassion and empathy towards his patient but also, takes ownership of your illness and lets you participate and voice the concerns regarding this illness. He listens and with professionalism, addresses each and every concern the patient might express with dedication and honest caring. I am finally home and positive that my distress and pain will be addresses and my outcome is in the best hands possible!

    5 out of 5 stars
    Reviewed on 9/23/2025

    Overall, it was a pleasant experience. The doctor reassured me that what I was doing to manage my condition was safe and effective.

    5 out of 5 stars
    Reviewed on 9/15/2025

    Dr. Overhiser is excellent! I have recommended him already to others.

    5 out of 5 stars
    Reviewed on 9/5/2025

    Overhiser is the best!

    5 out of 5 stars
    Reviewed on 8/28/2025

    I do really like Dr Overhiser and will continue to see him as long as he is in practice even if I have to travel further to do so.

    5 out of 5 stars
    Reviewed on 8/26/2025

    Exceptional experience

    5 out of 5 stars
    Reviewed on 8/19/2025

    Andrew is the best GF doctor that I could ever ask for.

    5 out of 5 stars
    Reviewed on 8/7/2025

    Dr. Overheiser is a caring and kind person.He listens to my concerns. He answers my questions in a way that I can understand. NAH is fortunat to have such a quality and devoted Doctor on their staff.

    5 out of 5 stars
    Reviewed on 8/6/2025

    Nothing bad to say at all

    5 out of 5 stars
    Reviewed on 8/5/2025

    Excellent

    5 out of 5 stars
    Reviewed on 7/25/2025

    Excellent provider.

    5 out of 5 stars
    Reviewed on 7/24/2025

    Outstanding Doctor. He paces himself appropriately. He doesn't present himself as being rushed. He explains everything.

    5 out of 5 stars
    Reviewed on 7/22/2025

    Dr Overhiser is terrific. I really liked, trusted and respected him. I liked that he was such a good listener and that I did not feel rushed. He gave me good guidance and perspective on my issue. He is a real asset to NAH.

    5 out of 5 stars
    Reviewed on 7/8/2025

    Dr Overhiser is the best, most caring and personal Doctor I have ever had. He talks to me and makes sure I understand what we talked about. I highly recommend him to anyone needing GI Dr.

    5 out of 5 stars
    Reviewed on 7/3/2025

    I was extremely impressed with Dr. Overhiser, his knowledge of my illness and how he handled everything!

    5 out of 5 stars
    Reviewed on 6/22/2025

    Dr Overhiser is the BEST. He's concerned, knowledgeable, current and caring! I'm so grateful to have him in Flagstaff

    5 out of 5 stars
    Reviewed on 5/22/2025

    Dr. Overheiser is very caring, listens to concerns, offers easy to follow recommendations and is very up-to-date on changes to treatments available!

    5 out of 5 stars
    Reviewed on 5/21/2025

    Dr. Overhiser is a great Doctor. He has let me have a say in my care plan and is always thinking and communicating with me my options. He also pays attention to my other health issues and considers them in my care plan. I feel very lucky to have him as part of my medical team.

    5 out of 5 stars
    Reviewed on 5/20/2025

    Dr Overhiser has wonderful communication skills and I appreciate his attention to me as a patient. NAH is fortunate to have him.

    5 out of 5 stars
    Reviewed on 5/20/2025

    EXCELLENT Doctor!!!!!

    5 out of 5 stars
    Reviewed on 5/14/2025

    Dr. Overhiser was very informed and listened to my list of questions. Each question I was answered and easily understood.

    5 out of 5 stars
    Reviewed on 5/13/2025

    Dr Overhiser is empathetic & up-to-date on cutting edge management of my condition.

    5 out of 5 stars
    Reviewed on 5/13/2025

    Since moving to northern AZ 20+ years ago I saw a couple other gastroenterologists. Dr. Overheiser is the first one who listens and wants to help me figure out my issues. I really appreciate his sincerity and professionalism. This is a very different experience than with the previous doctors.