Gastroenterology is the branch of medicine focused on the digestive system and its disorders. This includes the esophagus, stomach, small and large intestines, liver, pancreas, gallbladder, and bile ducts. Gastroenterologists are doctors specializing in this field, diagnosing and treating conditions like heartburn, irritable bowel syndrome (IBS), and inflammatory bowel disease (IBD). They also perform procedures like colonoscopies for colon cancer screening.