Rappahannock Gastroenterology Associates. Nursing (Nurse Practitioner), Gastroenterology • 3 Providers. 1500 Dixon St Ste 202, Fredericksburg VA, 22401. Make an Appointment. (540) 370-0430. Rappahannock Gastroenterology Associates is a medical group practice located in Fredericksburg, VA that specializes in Nursing (Nurse Practitioner) and ....