Find a Top Gastroenterologist Near Me in St. Louis, MO – Book an Appointment Instantly

Benjamin Root, MD, is board-certified in internal medicine and sees patients at Specialists in Gastroenterology in St. Louis, Missouri.

Dr. Root was born and raised in St. Louis and attended the University of Michigan in Ann Arbor for his undergraduate studies. He obtained his medical degree from Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia, Pennsylvania, before completing his internal medicine residency at New York University and his gastroenterology fellowship at Memorial Sloan Kettering Cancer Center in New York City.

Dr. Root cares for adults with a wide range of gastrointestinal disorders, with a particular emphasis on screening and surveillance of colorectal cancer, GERD/Barrett’s esophagus, functional GI disorders (including irritable bowel syndrome and function dyspepsia), and inflammatory bowel disease (including ulcerative colitis, Crohn’s disease, and a variety of liver diseases).

He is an active member of the American Society for Gastrointestinal Endoscopy, the American College of Gastroenterology, as well as in the American Gastroenterological Association.

After 15 years away, Dr. Root returned home to his beloved St. Louis, Missouri, to grow his GI practice. He is an avid Cardinals, Blues, and University of Michigan sports fan and continues to play ice hockey in his free time. He enjoys discovering new restaurants, attending concerts, going to the theater, and expanding his record collection.

Aman Singh, MD, is board certified in internal medicine and gastroenterology. At Specialists in Gastroenterology, she provides unparalleled care to patients in St. Louis, Missouri.

Dr. Singh was born in India and moved to St. Louis as a child. She received her medical training at the University of Missouri-Kansas City. Then, she completed her internal medicine residency in Ann Arbor, Michigan, and her gastroenterology fellowship at the University of Texas. In 2009, Dr. Singh returned to St. Louis to be closer to her extended family after four years of working at a private gastroenterology practice in Wisconsin.

Treating patients with a vast array of gastrointestinal issues is an important endeavor. Dr. Singh is a strong advocate for colon cancer screening and overall good digestive health. She has a special interest in working with patients with reflux, inflammatory bowel disease, and liver diseases. Ailments of the digestive tract can be difficult to pinpoint at times, and she works closely with her patients to listen to their concerns and find the most accurate assessment of their gastrointestinal problems.

As a woman of Indian descent who was raised in America, Dr. Singh is very sensitive to the gastrointestinal challenges associated with men and women from all walks of life, covering the spectrum of ethnically diverse and multi-cultural backgrounds. When evaluating and recommending a treatment plan, Dr. Singh considers factors including heredity, diet, physical examination, lab results, and other medically proven diagnostic methods.

Above all, Dr. Singh believes that being an empathetic listener and understanding her patients' delicate needs and issues are critical components for a successful physician-patient relationship.

Dr. Singh is married and is the mother of two children. In her spare time, she enjoys reading, gardening, and bicycle rides with her family.

Steven E. Fern, DO, is a board-certified gastroenterologist at Specialists in Gastroenterology in St. Louis, Missouri. 

Dr. Fern was born in Springfield, Massachusetts, and did his undergraduate work at the University of Dayton in Ohio. He is a graduate of the University of New England College of Osteopathic Medicine.

Dr. Fern is a fellow of the American College of Osteopathic Internists and is active in the teaching programs of several medical schools. He has lectured extensively on several GI topics locally, nationally, and abroad. He remains passionate about teaching other physicians and health care providers about colon cancer, colon cancer screening, performance of a quality colonoscopy, and wireless capsule endoscopy. 

He is a member of the American College of Gastroenterology, American Gastroenterological Association, American Society of Gastrointestinal Endoscopy, and the American Association for the Study of Liver Diseases. Dr. Fern is the President of the Saint Louis Capsule Endoscopy Club.

Dr. Fern cares for adults with gastrointestinal disorders with an emphasis on colon cancer screening, gastroesophageal reflux disease, Barrett’s esophagus, and inflammatory bowel disease (including ulcerative colitis and Crohn’s disease). His special interests include liver disease (including the treatment of patients with hepatitis C), and esophageal motility disorders. He has expertise in wireless capsule endoscopy, an endoscopic examination of the small intestine, as well as SmartPill™ Motility Testing.

Dr. Fern is married with three children. His leisure time activities include golf, reading, and attending sporting and cultural events. Although hardly a chef, his most favorite TV shows include shows like Hell’s Kitchen, Masterchef, and Top Chef. He has rediscovered his love for running and competes in marathons and half-marathon races around the country.

Board certified in both internal medicine and gastroenterology, Erik Thyssen, MD, currently sees patients at Specialists in Gastroenterology. He is dedicated to providing high-quality care to those living in and around St. Louis, Missouri.

Dr. Thyssen was born and raised in Denmark. After completing his medical degree, his desire to further his education led him to relocate to the United States and complete his internal medicine training at Michael Reese Hospital in Chicago, Illinois. He then completed his gastroenterology fellowship at Washington University in St. Louis, Missouri.

At Specialists in Gastroenterology, Dr. Thyssen sees adults with gastrointestinal disorders and uses endoscopic techniques in early detection and treatment. In addition, he has a voluntary teaching appointment in the Department of Medicine and Surgery at the Washington University School of Medicine. 

Dr. Thyssen and his wife, Carin, have three sons. Outside of work, he enjoys playing tennis and watching his wife perform on stage.

Curriculum Vitae

About Dr. Weinstock

Board certified in internal medicine and gastroenterology, Leonard Weinstock, MD, provides compassionate care to patients at Specialists in Gastroenterology in St. Louis, Missouri. 

Dr. Weinstock was born and raised in New York and moved to St. Louis in 1985. He received his medical training in Rochester, New York, and completed his gastroenterology fellowship at Washington University in St. Louis. 

He has a clinical teaching appointment as an Associate Professor of Clinical Medicine and Surgery at the Washington University School of Medicine. Dr. Weinstock’s lectures and research on diseases of the esophagus, stomach, small intestine, and colon have been presented at national and international conferences. He is actively researching the connection of the gut and small intestinal bacterial overgrowth (SIBO) with several medical problems, including restless legs syndrome and chronic pelvic pain syndromes. He presented several lectures in Oregon at the first SIBO symposium and in France at the international rosacea study group.

Dr. Weinstock provides individualized care to all adult patients with gastrointestinal disorders. His clinical practice emphasizes colon cancer screening, therapeutic videoendoscopy, motility disorders, management of irritable bowel syndrome, and comprehensive management of inflammatory bowel disease. His experience in treating IBS patients who have SIBO dates back to 2000. He has expertise in the use of low-dose naltrexone, which is one of the few modalities that promote the reduction of inflammation by increasing endorphins.

Dr. Weinstock is married and has twin daughters.

Nikhil Banerjee, MD, is board certified in both internal medicine and gastroenterology. He is committed to providing comprehensive care to patients at Specialists in Gastroenterology in St. Louis, Missouri. 

Dr. Banerjee was born in Los Angeles, California, and did his undergraduate work at Arizona State University in Tempe, Arizona. He is a graduate of the University of Utah School of Medicine and completed his residency at MedStar Georgetown University Hospital in Washington, DC, and a general gastroenterology fellowship at Loyola University Medical Center in Chicago. 

Dr. Banerjee spent an additional year of interventional training in endoscopic ultrasound, endoscopic mucosal resection, Barrett’s ablation, and endoscopic retrograde cholangiopancreatography at the Medical University of South Carolina. He is an active member of the American Society for Gastrointestinal Endoscopy and currently serves on the Education Products Committee.

He cares for adults with all gastrointestinal disorders with an emphasis on colon cancer screening, gastroesophageal reflux disease, Barrett's esophagus, all liver diseases (including hepatitis C and nonalcoholic fatty liver disease), and inflammatory bowel disease (including ulcerative colitis and Crohn's disease). His special interests include foregut tumors and pancreaticobiliary disorders (including pancreatic cyst diagnosis/management as well as acute and chronic pancreatitis).

Dr. Banerjee has started a minimally invasive hemorrhoid banding practice within the office that requires no anesthesia and minimal downtime. This procedure reduced symptoms from internal hemorrhoids by over 90% and has a robust effect.

He is married and has two young children. Dr. Banerjee’s leisure time activities include trying new restaurants, traveling, spending time with family, biking, and hiking.

As a board-certified gastroenterologist, Rajeev Ramgopal, MD, is skilled in providing high-quality, comprehensive care to patients experiencing a wide variety of gastrointestinal conditions. He is proud to be a part of the exceptional team at Gateway Gastroenterology, in Chesterfield, Missouri. 

After finishing his undergraduate education at the University of Rochester in New York, Dr. Ramgopal returned to his hometown of Oklahoma City to obtain his medical degree at the University of Oklahoma. He went on to complete his Internal Medicine Residency training at Washington University in St. Louis, Missouri, and was selected to serve as a chief resident. He stayed at Washington University to complete his Gastroenterology and Hepatology Fellowship.

When he is not caring for patients at Gateway Gastroenterology, Dr. Ramgopal enjoys spending time with his wife and son. He also likes to stay active by running, scuba diving, and snowboarding. He looks forward to welcoming new and returning patients to the practice.

Gateway Gastroenterology is pleased to welcome Taylor Geisman, MD.  Born and raised in St. Louis as the daughter of a gastroenterologist, Dr. Geisman completed her medical training at Washington University in St. Louis. She served as their Chief Resident before moving on to her specialty training in clinical Gastroenterology and Hepatology at Barnes-Jewish Hospital. She has prior research experience in Inflammatory Bowel Disease but her practice will include general Gastroenterology and Hepatology. Call to schedule your appointment with Dr. Geisman during office hours starting in May, 2024. 

Gateway Gastroenterology is pleased to announce that Dr. Fred Williams will be the Medical Director of our latest addition--Gateway GI Research, LLC.  This new research office will provide access for patients to participate in clinical trials close to where they live. 

Dr. Williams will be engaged in selected patient care activities while working with pharmaceutical and medical equipment companies to integrate research into our practice.  We are excited to introduce Gateway GI Research and Dr. Williams as its Medical Director.  

Articles About Dr. Williams:

-> Article #1

-> Article #2

-> Article #3

Plant-Based Nutrition Resources:

Nutritional Resources Handout

Jeffrey Mathews, MD, is committed to providing his patients with a wide range of gastroenterology services in a compassionate and timely manner at Gateway Gastroenterology, in Chesterfield, Missouri. He is board-certified in gastroenterology and hepatology.

Dr. Mathews is a life-long St. Louisan. He attended the University of Missouri – Kansas City Six-Year Medical School Program before going on to complete his fellowship in gastroenterology and hepatology at St. Louis University.

Making every effort to stay up-to-date on the latest advancements in his field, Dr. Mathews maintains active memberships with the American Society of Gastrointestinal Endoscopy and the American College of Gastroenterology.

At Gateway Gastroenterology, Dr. Mathews designs treatment plans unique to his patients' needs and concerns. He takes time to clearly communicate his treatment recommendations and encourages them to play an active role in their health care.

Dr. Mathews welcomes new patients to book an appointment by calling the practice or requesting an appointment online.

Board-certified gastroenterologist Richard Riegel, MD, sees patients at Gateway Gastroenterology in Chesterfield, Missouri. He strives to provide unparalleled care aimed at improving the digestive health of his patients.

A native of St. Louis, Dr. Riegel graduated with honors from the University of Missouri-Columbia School of Medicine. He then completed both his Internal Medicine internship and residency at Vanderbilt University in Nashville, Tennessee. 

From Vanderbilt, Dr. Riegel returned to St. Louis to complete three additional years of medical training in the Division of Gastroenterology/Hepatology at Saint Louis University.

Dr. Riegel is an active member of the American College of Gastroenterology and the American Gastroenterological Association.

Dr. Riegel has participated in the education and training of medical house staff at St. John’s Mercy Medical Center. He has a diverse practice specializing in all aspects of general gastroenterology, hepatology, and endoscopic procedures. He has been in private practice since 1997. He is married with three wonderful children.

Board-certified in gastroenterology and hepatology, dedicated physician Brian McMorrow, MD, provides a full range of care for gastrointestinal conditions. As part of the team at Gateway Gastroenterology, Dr. McMorrow is proud to serve the community of Chesterfield, Missouri with exceptional care. 

Dr. McMorrow completed his undergraduate studies at the University of California – Davis, earning his Bachelor of Science degree. From there, he moved to Missouri to pursue his medical degree at St. Louis University, where he would later also complete his internal medicine residency.

A member of the American Gastroenterological Association and the American Society for Gastrointestinal Endoscopy, Dr. McMorrow prioritizes ongoing education and makes every effort to stay on top of the latest developments in his field. 

When he’s away from the office, Dr. McMorrow is an avid runner, hiker, and part-time soccer coach. He welcomes new patients to Gateway Gastroenterology and looks forward to providing them with top-quality care.

Jason Haas, D.O. is dedicated to providing the highest quality of care to all his patients.  He has strong communication skills which allow him to connect with patients, staff and colleagues. 

For the past eight years, Dr. Haas has been a gastroenterologist practicing in Springfield, Missouri with Cox Medical Clinic.  He is a board-certified gastroenterologist that completed his GI Fellowship training at Aurora Health Care in Milwaukee, WI and his Internal Medicine Residency at Gundersen Health Care in LaCrosse, WI.  

His wife is from. St. Louis, and in their spare time Dr. Haas enjoys traveling with her and their two daughters.  Dr. Haas has been a member of the Colorectal Awareness Party in Springfield, which helps raise money and provide free colonoscopy evaluations for patients in need.

Gateway Gastroenterology is pleased to welcome Taylor Geisman, MD.  Born and raised in St. Louis as the daughter of a gastroenterologist, Dr. Geisman completed her medical training at Washington University in St. Louis. She served as their Chief Resident before moving on to her specialty training in clinical Gastroenterology and Hepatology at Barnes-Jewish Hospital. She has prior research experience in Inflammatory Bowel Disease but her practice will include general Gastroenterology and Hepatology. Call to schedule your appointment with Dr. Geisman during office hours starting in May, 2024. 

Gateway Gastroenterology is pleased to welcome Taylor Geisman, MD.  Born and raised in St. Louis as the daughter of a gastroenterologist, Dr. Geisman completed her medical training at Washington University in St. Louis. She served as their Chief Resident before moving on to her specialty training in clinical Gastroenterology and Hepatology at Barnes-Jewish Hospital. She has prior research experience in Inflammatory Bowel Disease but her practice will include general Gastroenterology and Hepatology. Call to schedule your appointment with Dr. Geisman during office hours starting in May, 2024. 

As a board-certified gastroenterologist, Rajeev Ramgopal, MD, is skilled in providing high-quality, comprehensive care to patients experiencing a wide variety of gastrointestinal conditions. He is proud to be a part of the exceptional team at Gateway Gastroenterology, in Chesterfield, Missouri. 

After finishing his undergraduate education at the University of Rochester in New York, Dr. Ramgopal returned to his hometown of Oklahoma City to obtain his medical degree at the University of Oklahoma. He went on to complete his Internal Medicine Residency training at Washington University in St. Louis, Missouri, and was selected to serve as a chief resident. He stayed at Washington University to complete his Gastroenterology and Hepatology Fellowship.

When he is not caring for patients at Gateway Gastroenterology, Dr. Ramgopal enjoys spending time with his wife and son. He also likes to stay active by running, scuba diving, and snowboarding. He looks forward to welcoming new and returning patients to the practice.

Gateway Gastroenterology is pleased to announce that Dr. Fred Williams will be the Medical Director of our latest addition--Gateway GI Research, LLC.  This new research office will provide access for patients to participate in clinical trials close to where they live. 

Dr. Williams will be engaged in selected patient care activities while working with pharmaceutical and medical equipment companies to integrate research into our practice.  We are excited to introduce Gateway GI Research and Dr. Williams as its Medical Director.  

Articles About Dr. Williams:

-> Article #1

-> Article #2

-> Article #3

Plant-Based Nutrition Resources:

Nutritional Resources Handout