Ernesto Guerra Jr., M.D.



520 E Euclid Ave

San Antonio, TX 78212

Open today 8 AM - 5 PM

Quick Facts

  • Virtual Telemedicine Visits Available, Call For Details
  • Board Certified Gastroenterologist
  • Currently Accepting New Patients
  • Most Insurance Plans Accepted
  • Performs Colonoscopies
  • Fluent in English and Spanish

SAGA - San Antonio, TX - Downtown

Gastroenterology in San Antonio, TX

SAGA - San Antonio, TX - Downtown

520 E Euclid Ave

San Antonio, TX 78212

Open today 8 AM - 5 PM

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About Ernesto Guerra Jr., M.D.


Ernest Guerra, Jr., M.D. completed his Medical Doctorate at the University of California in San Diego and both internship and residency at the University of Texas Health Science Center in San Antonio. During his residency, Dr. Guerra served as Chief Resident of Internal Medicine and discovered his true calling, the subspecialty of gastroenterology.

While completing his Fellowship in Gastroenterology, Dr. Guerra then became fascinated with the innovative and technical nature of the profession. He says, “Looking back, it is amazing what has changed in the field [of gastroenterology] over just the last 20 years.” He then says, “I never thought in my lifetime we would see some of the advancements or cures that have been developed.”

Dr. Guerra is not just a witness to the advancements in GI but has also been an integral figure in industry changes in San Antonio. He founded the SAGA group, pioneering the concept of a freestanding endoscopy center, opening the first of its kind in downtown San Antonio. “It is one of the most pivotal experiences of my life. It was challenging, and anything we have achieved has been hard-won, but we did it to offer better service and a higher quality of care to our patients. And that is still our mission today.”

This mission has led the prestigious group to grow to eight clinic offices and three endoscopy centers in the San Antonio area, boasting some of the highest patient satisfaction ratings in the state, as well as exceeding industry quality standards across the nation.

If you ask Dr. Guerra what he loves about practicing medicine today, he will say, “Patient education. We do a lot for the patients that make it through our doors, but we are always seeking to do even more to reach more people who could benefit from these life-saving procedures.”


Doctor of Medicine, University of California, San Diego, California

Internship, Residency, Internal Medicine, University of Texas Health Science Center, San Antonio, Texas

Fellowship, Gastroenterology University of Texas Health Science Center, San Antonio, Texas


Founding Physician, University of California, San Diego, California

Medical Director, San Antonio Gastroenterology and Endoscopy Center, San Antonio, Texas

Chair, Medical Executive Committee of San Antonio Gastroenterology Endoscopy Centers

Member, American College of Physicians

Member, American Society of Gastrointestinal Endoscopy

Member, Bexar County Medical Society



Dr Guerra is the most caring doctor I have ever seen. He took the time to listen to all my concerns about my condition. He explained the treatment plan very clear and made sure I understood everything. His office staff was very polite and professional specifically his assistant Nate who was excellent. Office visits was about one hour and went really smooth.

J.G. Google

As always, seeing Dr. Guerra makes me feel so much better. He listens to my concerns and takes action when needed.

E.S. Google

Dr Guerra and his team always treats there patients with the best care possible. I always have a great feeling that your health is in good hands with their team.

J.G. Google

Best gradpa ever

A.R. Google

The services were excellent.

S.V. Google


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