Gastroenterology is the branch of medicine focused on the digestive system and its disorders. Gastroenterologists diagnose and treat conditions affecting the esophagus, stomach, small intestine, large intestine (colon), rectum, pancreas, gallbladder, bile ducts, and liver. They use various diagnostic procedures and medical treatments to manage issues such as acid reflux, ulcers, irritable bowel syndrome, inflammatory bowel disease, hepatitis, and pancreatitis.