COVID-19 Guidelines

CU Doctors are here for you!
Our clinics are open and able to serve you during this time for urgent in-person visits as well as virtual health services. Please call our clinics directly to schedule an appointment for both in person and virtual health.

Our number one priority is the health and safety of our patients, their family members, as well as our health care team. To honor this commitment we have implemented the following procedures:

  • Non-urgent medical appointments should be converted to telehealth visits or rescheduled if telehealth is not feasible.
  • Please bring your own face mask or covering to wear. Patients checking in must tell staff if they have: A fever, cold symptoms (cough, sore throat, runny nose, shortness of breath); Flu symptoms (fever, chills, body aches, etc.).
  • Adult patients may be allowed one asymptomatic person (at least 17 years old) for support; however, we reserve the right to deem a support person unnecessary at any time.
  • Pediatric patients may be allowed one asymptomatic adult (i.e. parent, guardian) for support.
  • For pediatric patients, please check the Children's Hospital Colorado website for updated COVID-19 related patient information.

Please call us about your current health care concerns. Please take care in following current public health guidelines. Please visit the Colorado COVID-19 website, for more information.

Thank you for doing your part to help keep everyone safe and healthy!

Dennis Ahnen, MD
Associate Professor Emeritus, Medicine

Clinic (303) 399-8020
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Gender: Male
Languages: English
Department, Section/Division: Medicine

Practice Locations

University of Colorado Hospital (UCH)
12605 E. 16th Ave
Aurora, CO 80045
More providers at this location

Denver Veterans Affairs Medical Center
1055 Clermont St
Denver, CO 80220
More providers at this location

Hospital Affiliation
  • Veterans Affairs Medical Center
  • University of Colorado Hospital

Specialty Information

  • Internal Medicine - Gastroenterology, Board Certification (1985)
  • Internal Medicine, Board Certification
Conditions & Treatments
  • Cancers
  • Colorectal Cancer
  • Digestive System
  • Colonoscopy
  • Gastroenterology (Stomach, Bowel, General GI Problems)



Information for Referring Providers

Clinical Interests for Referring Providers
Colon Cancer Prevention, General Gastrointestinal Disorders

Research Interest for Referring Providers
At the basic level the Ahnen Lab is examining the biologic and the biochemical mechanisms of the chemopreventive effects of the non-steroidal anti-inflammatory drugs (NSAIDs). The lab is currently examining the effect of NSAIDs on EGF receptor expression and function. Dr. Ahnen collaborates closely with the laboratory group of Pamela Rice, PhD a faculty member in the Division on this basic science work. Dr. Ahnen's clinical trials group participates in several colorectal cancer prevention trials including several adenoma chemoprevention trials. Dr. Ahnen also collaborates with Al Marcus PhD and staff at the AMC Cancer Research Center to evaluate behavioral interventions to increase colorectal cancer screening rates in high-risk populations and he directs the Colorado site for two national cancer registries that identify high risk families for genetic and clinical trials.

Clinic Phone: (303) 399-8020
Contact Us
In An Emergency: Please Dial 911

University of Colorado Medicine (CU Medicine)
Refer a Patient: 720-848-2828
Billing Questions: 303-493-7000

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