About Gastroenterology

Gastroenterology is the specialty of medicine that provides care for diseases affecting the gastrointestinal tract, from the mouth to the anus, namely the esophagus, stomach, small intestine and large intestine (colon), liver, gallbladder, and pancreas.

Services Provided

Focusing on the evaluation and treatment of gastroenterology disorders, a gastroenterologist does not perform surgery. Instead, he does perform procedures such as liver biopsies and endoscopic examinations of the esophagus, stomach, and small and large bowel. In evaluating your gastroenterology condition, your HMG gastroenterologist will work closely with your primary care provider and, if surgery is needed, your surgeon, in providing follow-up care relevant to your particular digestive disorder.

Your Initial Appointment

Please arrive 10 to 15 minutes prior to your scheduled appointment in order to complete new patient documentation.

  • Lawrence Bailey, MD received his undergraduate degree from the University of Virginia in Charlottesville, VA, and his medical doctorate degree from the Medical College of Virginia in Richmond, VA.

    The recipient of multiple awards and honors, Dr. Bailey has nearly three decades of experience in treating gastroenterology-related conditions and diseases.

  • Adam Coe, MD is a native of Abingdon and grew up on a family farm, where he learned early on about the cycle of life. Born with a health condition, Dr. Coe was no stranger to the healthcare field. His experience as a child ultimately led him to pursue a career in medicine. The dedicated care he received as a child sparked his passion for medicine, motivating him to offer the same compassionate care that had inspired him.

  • Erika Grigg, MD grew up watching her father practice internal medicine and knew she wanted to pursue medicine like him. She started her medical school journey with a concentration in dermatology, but as she continued her education and was exposed to the field of gastroenterology while doing her internal medicine rotation, she fell in love with the field of gastroenterology.

  • Jennifer Phemister, MD treats a broad range of gastroenterological diseases, including pancreas, stomach, and colon disorders.

    The variety of procedures, as well as inpatient and outpatient treatments, drew her to gastroenterology. Having Dr. Phemister on staff gives patients the option of choosing either a male or a female gastroenterologist.

  • Dallas Shone, MD is board certified in Gastroenterology by the American Board of Internal Medicine. After completing his residency at Presbyterian University of Pennsylvania Medical Center, he completed his gastroenterology fellowship at John Hopkins Bayview Medical Center in Baltimore, Maryland.

    With over three decades of experience, Dr. Shone has been with Holston Medical Group since 1994.

  • James Swenson, MD was fascinated by biology and medicine and knew he wanted to become a doctor. “I have always loved medicine and I still love it after 30 years,” said Dr. Swenson. Dr. Swenson has performed approximately 40,000 endoscopic procedures during his career.

    Dr. Swenson completed his residency at Bethesda Naval Hospital in Bethesda MD, and his doctorate of medicine at St. Louis University School of Medicine in St. Louis, MO.

  • A native of Southwest Virginia, Jacquelyn Baker, FNP received her Bachelor of Science in Nursing from East Tennessee State University in Johnson City, TN, and her Master of Science in Nursing from Lincoln Memorial University in Kingsport, TN.

    Jacquelyn Baker, FNP has been with HMG since 2019.

  • A native of Northeast Tennessee, Amanda Campbell, FNP received her Master of Science in Nursing at Middle Tennessee State University, Murfreesboro, TN, and her Bachelor of Nursing at East Tennessee State University, Johnson City, TN.

    Nurse practitioner, Amanda Campbell, FNP has been with HMG since April 2021.

  • A native of Southwest Virginia, Ashlee Fleming, FNP received her Bachelor of Science in Nursing from King University in Bristol, TN, and her Master of Science in Nursing from Chamberlain University.

    She is a member of the American Association of Nurse Practitioners, American Association for the Study of Liver and Diseases Oncology Nurses Association.

  • Rhonda Ragsdale, FNP, a native of Southwest Virginia, earned her Master's Degree and undergraduate degree from East Tennessee State University.

    With a specialization in gastroenterology, she has been a valuable member of the HMG team since 2009, providing care to both adults and children for gastrointestinal issues.


The most common gastroenterology procedures include endoscopy, liver biopsy, ERCP, colonoscopy (tradition & virtual), and PEG tube placement.

Most gastroenterology procedures are performed at these facilities:

Further, our doctors are trained in minimally invasive techniques designed for reduced incision size, reduced pain, and reduced recovery time.

The most common gastroenterology procedures include endoscopy, liver biopsy, ERCP, colonoscopy (tradition & virtual), and PEG tube placement. Most gastroenterology procedures are performed at:

The virtual colonoscopy is performed at HMG’s Outpatient Diagnostic Center at MeadowView Lane.

The Virtual Colonoscopy

Thanks to leading-edge technology like the new “virtual colonoscopy” introduced at HMG’s Outpatient Diagnostic Center at MeadowView Lane, patient screening measures for one of the most preventable types of cancer—colon cancer—just got an incredible boost. Learn more about virtual colonoscopies.

Procedural Preparation

Most gastroenterology procedures require advanced patient preparation. You may view prep instructions by selecting the various procedures listed:

Unable to keep your appointment?

If you find that you are going to be unable to keep your appointment, out of courtesy to patients who are desiring appointments, please provide us advance notice as early as possible. We request at least a 24-hour advance notification for office appointments.