Kevin S. Sieja, M.D.


13701 East Mississippi Ave Suite 380

Aurora, CO 80012

Quick Facts

  • Virtual Telemedicine Available
  • Board Certified Gastroenterologist
  • Performs Colonoscopies
  • Currently Accepting New Patients
  • Most Insurance Plans Accepted

CG Aurora, CO

Gastroenterology in Aurora, CO

Colorado Gastroenterology - Aurora, CO

13701 East Mississippi Ave

Suite 380

Aurora, CO 80012

Closed. Opens Mon at 8:30AM


CG Denver - N Ogden St

Gastroenterology in Denver, CO

Colorado Gastroenterology - Denver, CO - N Ogden St

1960 N Ogden Street

Suite 220

Denver, CO 80218

Closed. Opens Mon at 8:30AM


CG Denver - Endoscopy Center

Gastroenterology in Denver, CO

Colorado Gastroenterology - Denver Endoscopy Center

8155 E 1st Ave

Denver, CO 80230

Closed. Opens Mon at 8:30AM

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About Kevin S. Sieja, M.D.

Dr. Kevin Sieja is a board-certified Gastroenterologist with Colorado Gastroenterology. He performs routine GI procedures such as upper endoscopy and colonoscopy in the diagnosis, screening and surveillance of gastrointestinal diseases and cancers. He has served as managing partner for his practice for over 10 years. He is a member of the American Gastroenterological Association and American Society of Gastrointestinal Endoscopy.


Undergraduate: University of Notre Dame

Medical School: Northwestern University

Residency & Fellowship: University of Colorado Health Sciences Center

Why did you choose to specialize in Gastroenterology?

Gastroenterology is one of the most interesting fields in medicine as it combines technologically advanced procedures with the thoughtful practice of medicine. It is an intellectually and emotionally rewarding profession. I manage conditions across the multiple organs that make up the gastrointestinal tract. I am often able via procedures to directly visualize and diagnose conditions firsthand and then prescribe appropriate medical treatment based on those findings or in some cases to address the problem during the procedure. The specialty also allows me to develop long term relationships with many patients such as those with inflammatory bowel disease and irritable bowel syndrome. Finally, with a focus on colon cancer screening and prevention through colonoscopy, I can help reduce the incidence of the second leading cause of cancer death on a daily basis.

Do you have a specialty of interest in Gastroenterology?

I treat all conditions and diseases of the gastrointestinal tract and liver.

What do you and your family enjoy doing in your spare time?

We enjoy spending time at home with our family and two dogs. And we value our time together in the outdoors on the mountains, valleys, and waters of beautiful Colorado

Awards and Accreditation:

I graduated summa cum laude from the University of Notre Dame and while in medical school at Northwestern, I became a member of the prestigious Alpha Omega Alpha Honor Medical Society. I have served as Managing Partner of the practice for over 10 years.


Board Certified in Gastroenterology

Professional Affiliations

American Gastroenterological Association

American Society for Gastrointestinal Endoscopy


Dr. Sieja listened to what was ailing me during my visit and straightforward on what needed to be done next. I was happy with my visit.

E.C. Google

Dr. Sieja listed to what I had to say. Scheduled appointments for me the very next day, in order to get to the root of my problem. I am thankful for having him as my doctor.

L.M. Google

Dr. Sieja is extremely knowledgeable, professional and friendly. I know I am in good hands and getting great advice. Thank you!!!

A.S. Google

Very good, positive experience.

L.M. Google

Dr. Kevin Rufner is very thorough, knowledgeable and excellent. I definitely recommend him. Thanks, Virginia

V.F. Google


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