Douglas B. Kliewer, MD

Douglas Kliewer, MD chose a career in medicine because he truly appreciates the opportunity to care for others and engage in scientific research and study to help solve his patients’ medical concerns. When choosing a subspecialty, gastroenterology seemed like a natural choice. Dr. Kliewer recalls, “There was always something to do and the advancements in the field were so groundbreaking and impactful.”

Dr. Kliewer graduated from Oklahoma State University with an undergraduate degree in Physiology, and attended medical school at the University of Oklahoma College of Medicine, graduating with Outstanding Distinction. He completed his internship and residency in Internal Medicine at the University of Texas Southwestern Medical Center in Dallas, then moved on to complete two fellowships at UT Southwestern: one in Gastroenterology and Hepatology and one in Advanced Therapeutic Endoscopy.

Dr. Kliewer’s specific area of interest in the GI field is in the treatment of Inflammatory Bowel Disease (IBD). As a physician of Adult Gastroenterology Associates (AGA), Dr. Kliewer is proud to be a part of a group that upholds high-quality standards of care for each patient. Every physician strives to be available to their patients, colleagues, and the community the facility serves.

Over his last 20 years with Adult Gastroenterology Associates, Dr. Kliewer has seen tremendous advancements in the treatment of IBD, including new medications to treat the root cause and manage symptoms. New technology has also emerged, such as video capsule cameras that can travel farther along the GI tract than was ever previously possible. EMR (Endoscopic Mucosal Resection) has also been a groundbreaking procedure, allowing gastroenterologists to remove areas of diseased tissue four to five times larger than a typical biopsy. This eliminates the need for traditional surgery and is much safer for the patient.

Outside of work, Dr. Kliewer enjoys photography, travel, and activities at his church.

I try to provide my patients with thoughtful care and attention to detail. I want to provide them the time I would want from my doctor, even if it puts me behind in my schedule!– Douglas Kliewer, MD Adult Gastroenterology Associates, Tulsa, OK

Education, Memberships, Awards, and Affiliations

  • Bachelor of Science in Physiology: Oklahoma State University – Stillwater, OK
  • Doctor of Medicine: University of Oklahoma College of Medicine – Oklahoma City, OK
  • Internship and Residency in Internal Medicine: University of Texas Southwestern Medical Center – Dallas, TX
  • Fellowship in Gastroenterology and Hepatology: University of Texas Southwestern Medical Center – Dallas, TX
  • Fellowship in Advanced Therapeutic Endoscopy: University of Texas Southwestern Medical Center – Dallas, TX
  • Coburn Medical Scholarship recipient while at the University of Oklahoma
  • Phi Kappa Honor Society (top 10% of his class) at Oklahoma State University
  • Alpha Omega Alpha Medical Honor Society
  • American Gastroenterological Association
  • American College of Gastroenterology
  • American Society for Gastrointestinal Endoscopy
  • Christian Medical and Dental Society


  • Gastroenterology
  • Internal Medicine



Practicing medicine since 1997



Adult Gastroenterology Associates


Tulsa Endoscopy Center

4200 Skelly Dr., Suite 100
Tulsa, Oklahoma 74135

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