All our professionals at Gastroenterology of San Marcos maintain the highest level of accreditation and pursue ongoing education to stay abreast of the latest trends in gastroenterology.

Gastroenterology of San Marcos is the home of outstanding physicians, excellent nurses, and caring staff. Our main goal is to ensure our patients receive the highest quality of care in a professional and comfortable environment. The Central Texas Ambulatory Endoscopy Center continues to maintain three-year AAAHC certifications (the longest allowable) and received a perfect reviews in 2004, 2007, and 2010.  We have been at the forefront of the industry for years now, and have already been using electronic health records for the past 3 years.  We continue to employ the most technologically advanced equipment and cutting-edge procedures to bring our patients state-of-the-art care and achieve the best outcomes possible.

Our physicians are recognized both locally and throughout the region as some of the top authorities in the field.  Dr. Kern Deschner has been appointed to the Texas Board of Medical Examiners as a subspecialty reviewer in the field of Gastroenterology. Dr. Coles serves on the board of Christus Santa Rosa Out Patient Surgery Center and the CSR Advisory Hospital Board.  Our physicians continue to be named among the "Top Doctors" in the state for nearly a decade.

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Edward F. Coles, MD, FACP, FACG

Dr Coles did his premedical undergraduate work at the University of San Diego. In 1980, he graduated Summa Cum Laude with a BA in Mathematics and went on to pursue his degree in medicine from Georgetown University in Washington DC. In 1981, he received a health professional scholarship to help pay for his education and was then able to marry Lorrie two days later. He proved to be an exceptional scholar while at Georgetown, served as Vice President of the Alpha Omega Alpha Medical Honor Society, and, in 1984, graduated Cum Laude. After medical school, he completed his internship and residency in Internal Medicine at Letterman Army Medical Center in San Francisco, California. During this time, he received several honors including the “Top Teacher Award” which is given by the intern class to one resident and the “Top Over-all Graduate Award” which encompasses all specialties at the medical center. In 1989, he completed his fellowship in Gastroenterology at Brooke Army Medical Center and then accepted a teaching position at Letterman in San Francisco and UCSF. Eventually, he became Chief of Endoscopy followed by Chief of Gastroenterology at Letterman. He published original research and lectured at many local and national venues. Then, in 1992, he entered into a private practice of Gastroenterology with Dr. Deschner in San Marcos and New Braunfels, Texas. At the time, they were the only Gastroenterologists for 5 counties and 5 hospitals, but over the years the practice has flourished and now consists of 5 partners.
Dr. Coles has remained an active member of the board of directors of the New Braunfels Christus and Physicians Surgery Center since its founding as McKenna Surgery Center in the 1990's. He founded the Central Texas Ambulatory Endoscopy Center in San Marcos, Tx, and serves as managing partner. For many years, Dr. Coles has served on the Christus Santa Rosa Hospital Community Advisory Board and on many committees within the Central Texas Medical Center and Christus Santa Rosa Hospital in New Braunfels. He was named a top gastroenterology consultant for the Austin area in Austin Monthly Magazine by his physician peers in 2001 and has been given that honor nearly every year since. For the last several years, he has been tapped as a Top Doctor in Texas by the Texas Monthly Magazine.
      Ed and Lorrie have been married over 30 years and have 4 children. He is active in the community, loves his practice of Gastroenterology, and takes pride in providing personal, professional consultations and procedures in their state of the art facilities.
   Dr. Coles is board certified in Internal Medicine and Gastroenterology.


W. Kern Deschner, MD

Dr. William Kern Deschner graduated Magna Cum Laude with a degree in Marine Biology from Texas A&M University. In 1979, he chose to pursue a degree in medicine from Baylor College of Medicine. He was an exceedingly gifted student, gaining membership into the Alpha Omega Alpha Medical Honor Society in addition to receiving Honors in Basic Sciences. Dr. Deschner graduated with honors in 1983, completed his internship and residency at Baylor Affiliated Hospital in 1986, and began his fellowship in Gastroenterology at Georgetown University Hospital in Washington D.C. During this time, he served as Clinical Instructor of Medicine/ Gastroenterology and, in 1988, he received the prestigious Lawlor Award for Best
Scientific Paper from the American College of Gastroenterology. In 1989, he accepted a position as Assistant Professor in the Department of Internal Medicine Division of Gastroenterology at the University of Texas Medical Branch. He then moved to San Marcos where he entered into a private practice of Gastroenterology.

Dr. Deschner is board certified in Internal Medicine and Gastroenterology. He has served as Director of Endoscopy and Chairman of the Department of Medicine at Central Texas Medical Center. In addition, he has held numerous other leadership positions including: President of the Tri-County Medical Society, Texas Medical Association House of Delegates, and member of the Board of Advisors for the Texas Society for Gastroenterology and Endoscopy.

Dr. Deschner and his wife Rhonda have been married since 1983. They have four children, Austin, Michelle, Mark, and Ethan. He is an involved member of Cypress Creek Church, serves as Scoutmaster for Troop 1907, and is a contributing author to the Newsletter of Lone Star Bonsai Federation. A devoted father, husband, and physician, he remains passionate about his profession and dedicated to providing the highest quality of care.


Thomas Kepczyk, MD, FACP, FACG

Dr. Thomas Kepczyk excelled in his undergraduate work at Arizona State University. In 1982, he graduated Summa Cum Laude with a BA in Chemistry and went on to pursue a degree in medicine from the University of Arizona. During his academic career, he proved to be a brilliant scholar and received numerous awards and memberships into coveted societies including: Alpha Omega Alpha Medical Honor Society, Phi Beta Kappa, and Phi Beta Phi. After graduating Summa Cum Laude from medical school in 1986, he moved to Texas to complete his internship and residency in Internal Medicine at Brooke Army Medical Center. In 1989, Dr. Kepczyk was selected as the “Outstanding Resident in Ambulatory Care” at BAMC. He gained further experience at the 67th Evacuation Hospital in Wuerzburg where he served as a Staff Internist and then Chief of Medicine. In July of 1991, he returned to Brooke Army Medical Center to complete his fellowship in Gastroenterology, and then, in 1993, he accepted a position as a staff gastroenterologist at Fitzsimons Army Medical Center in Colorado. During this time, he accepted the position of Clinical Instructor in the Department of Medicine at the University of Colorado. In 1995, he moved back to Texas and entered into private practice at Gastroenterology of San Marcos and New Braunfels.

            Dr. Kepczyk is board certified in Internal Medicine and Gastroenterology. He serves as an active member on the board of the Central Texas Ambulatory Endoscopy Center and on the board of McKenna Ambulatory Surgical Center. He is a Fellow in the American College of Physicians as well as the American College of Gastroenterology and remains a part of other professional organizations including the American College of Gastrointestinal Endoscopy. In addition, he is a member of the Primary Care Committee and serves as Director of Nutrition at Central Texas Medical Center.

            Dr. Kepczyk was born in Berlin, Germany, moved to the United States with his family at age 5, and now calls Texas home. He and his wife Barbara have 2 sons, Alexander and Nicholas. He remains a devoted father and husband, serves as an active member in his community and church, truly loves his profession and takes pride in providing the utmost in quality of care.


Shannon J. Marek, MD

Dr. Marek was born and raised in Texas, growing up working in his family’s automotive business outside of Dallas. As a first generation college student, Dr. Marek attended Baylor University on Presidential scholarship. While there he excelled in the advance coursework involved with the Interdisciplinary Core, participated in the Honors program, and served in the Baylor Chamber of Commerce. He graduated cum laude with a Bachelors of Arts degree in Psychology. He then went on to receive his Doctorate of Medicine from the University of Texas at Houston Medical School. His internal medicine internship and residency was then at the University of Alabama at Birmingham, one of the top 10 internal medicine programs in the nation. While there, he received multiple awards, including a peer elected award naming him one of the top overall residents. Thereafter, the combination of intellectual challenge and procedural technique led him to training in Gastroenterology at the Medical College of Georgia. He has presented at multiple national conferences, and helped to author a preeminent textbook in the field of GI.

      Dr. Marek has trained in numerous aspects of advanced endoscopy, including EGD, Colonoscopy, and ERCP. He has extensive training in luminal stent placement, endoscopic mucosal resection, and wireless capsule endoscopy. He is also trained in hemorrhoid banding using the CRH O’regan system; the most advanced, pain free method of nonsurgical hemorrhoidal treatment. Dr. Marek maintains a commitment to ensure the latest advancements in therapy are available for the benefit of his patients. He is board certified in both Internal Medicine and Gastroenterology.

      In 2001, Dr. Marek had the privilege of marrying his beautiful wife Shanan. They have 3 children, Cole, Mason, and Grant with a golden retriever named Jake. Their family is actively involved in Oakwood Baptist Church in New Braunfels, TX. When not at work; spending time with family, friends, and church activities are top priorities. He enjoys all things outdoors including hunting, fishing, hiking, biking, and even the occasional sprint triathlon. As a physician with humble beginnings and a loving family to keep him grounded, Dr. Marek strives to translate the complex medical world into an understandable experience for his patients.


Carlos A. Neghme, MD

Dr. Carlos A. Neghme excelled in the Undergraduate Honors Program at Loyola University in Chicago, Illinois. In 1987, he graduated Cum Laude with a Bachelor’s degree in Science. He was then accepted into the College of Medicine at the University of Illinois and received his Doctorate of Medicine in 1991. He remained in Chicago to continue his medical training. He completed his residency in Internal Medicine at the University of Loyola Medical Center and, in 1996, specialized in the field of Gastroenterology. During his time at Loyola University, Dr. Neghme became proficient in endoscopic procedures and in clinical evaluation of patients. Under the guidance of highly respected and well-known professors, he trained with the most advanced endoscopic equipment. As an expert in the field, he is remarkably skilled in Upper Endoscopy, Colonoscopy, and Biliary Endoscopy procedures. He has participated in research analyzing Colon Cancer and Polyp Prevention, Ulcerative Colitis, and Hepatitis C.

      Dr. Neghme is originally from Chicago, Illinois but has made Texas his home. He has been practicing in the field of Gastroenterology for over a decade and is now an esteemed partner at Gastroenterology of San Marcos and New Braunfels. He has a true passion for his profession and each patient is ensured the utmost in quality of care.


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