Diseases affecting the gastrointestinal tract, including organs along the digestive tract from the mouth to the anus, are the focus of this major. Doctors who practice in this field are called gastroenterologists. Usually, they have completed about eight years of medical and pre-medical education, one year of internship (if this is not part of the residency), three years of internal medicine residency, and three years of gastroenterology scholarships. Gastroenterologists perform many diagnostic and therapeutic procedures, including colonoscopy, Esophagogastroduodenoscopy, endoscopic retrograde cholangiopancreatography, Endoscopic Ultrasound (EUS), and liver biopsy
