Patient Reviews

We understand that finding a provider that will truly listen to your concerns isn’t always easy. At Adult Gastroenterology Associates, our patients are our top priority. We strive to create a thoughtful and compassionate environment where you can trust that your care is customized to your needs. Take some time to browse through our reviews below, so you can read first-hand about the dedication and care that our specialists provide patients in the Tulsa, OK community.

5.0 Review from D.M. Source: Google May 26 2023

"This is Joyce McCoy I have been a patient of Dr Nightingale for over 18 years.. he is the BEST ! I have PBC and he takes care of me 100% I do all my endoscopy and colonoscopy there at his office on Kelly Dr. In Tulsa"

5.0 Review from B.S. Source: Google Dec 25 2022

"Absolutely a wonderful experience. This was the first time I met Dr. Nightengale for my first colonoscopy potential need. I felt like he had been my physician for years. He made me feel completely comfortable and answered all my questions respectfully and thoroughly."

5.0 Review from J.C. Source: Google Nov 25 2022

"Dr. Nightengale has been my gastroenterologist for over 20 years. In my opinion he is as knowledgeable in his field as any person could be. He is very efficient in his consultations with you. No questions left unanswered. I have had multiple EGD’s as well as colonoscopies and his review of the results is always very thorough. I highly recommend Dr. Nightengale."

5.0 Review from S.A. Source: Google Nov 25 2022

"I have known Dr Mark Nightengale for years, have trusted his colonoscopy experience and will continue to reschedule whenever he recommends. A great friend as well."

5.0 Review from D.W. Source: Google Oct 25 2022

"Dr. Nightingdale's staff is Tulsa's best in colonoscopy's in my opinion. His staff has preformed my last 4 colonoscopys. Each time his staff was always very professional and courteous. I was in and out in under 1 hour. I will go back to him for my next one as well! I can't say enough Great surgeon Great Staff!!!"

5.0 Review from P.U. Source: Google Aug 25 2022

"I was pleased with the services that I received from Dr. Nightengale and staff for my colonoscopy/endoscopy procedure."

5.0 Review from A.T. Source: Google May 25 2022

"I recently had a colonoscopy and an upper GI which Dr Markham Nightengale performed. I was totally happy with his services and my care from his staff. I was complete informed on how to take my prep and how it would work. I arrived on time the next morning and filled out my papers I was taken back to get prepared and his staff was so nice and told me exactly what they were going and how it would go. When it was my turn and by the way it was on time I was taken back and they did the procedures and then off I went to recover. Everyone that I came in contact with was so nice and pleasant. For a procedure no one looks forward to it was no problem and Dr Nightengale came in before I left to let me know what he had done and that he had told my husband already. I was completely satisfied with my experience with him. Thank you Dr Nightengale"

5.0 Review from C.J. Source: Google May 25 2022

"If you have to have a colonoscopy this is the place to go, they are so nice. They make everything as comfortable as possible. They stay on schedule . Dr. Nightingale has a good bedside manner"

5.0 Review from B.D. Source: Google May 25 2022

"Just completed 3rd colonoscopy procedure done by Dr. Nightengale. He spoke with me prior to the procedure in his usual pleasant manner. A detailed report including photos was provided afterwards. Checking in at the lobby was efficient. Initial prep by nurse and anesthesiologist went smoothly. Checkout also. All staff from checkin to checkout were pleasant."

5.0 Review from G.N. Source: Google May 25 2022

"This was as good as it gets for a colonoscopy. Everyone was very cordial and professional. Had absolutely no complications from procedure. See you in five years!"

5.0 Review from S.C. Source: Google May 25 2022

"Very thorough by listening and asking questions to get the best diagnosis and care. He is friendly and personable. I was at ease when I left the office knowing the best way to take care of my problem is to have a colonoscopy/endoscopy to get a thorough diagnosis. I asked questions that he took the time to answer and explain his answers. I highly recommend Dr. Nightengale. He is an excellent gastroenterologist!"

5.0 Review from M.L. Source: Google May 25 2022

"Been going to Dr. Nightingale since I had my first colonoscopy 30 years ago. He is very friendly, direct, professional, concerned about you when speaking with you. He’s a great person. His staff is very helpful and professional. The center where the procedures take place is clean and comfortable. Both the Dr.’s office and the center are taking Covid precautions."