Gastroenterology is a subspecialty of medicine that involves the study of the entire gastro-intestinal system which includes the function of the esophagus, stomach, small intestines, large intestines, rectum, liver, bile ducts, gallbladder, and pancreas. Gastroenterology focuses on the study of the movement of ingested material through the gastrointestinal tract (otherwise known as motility), digestive and absorptive processes, and waste removal. Also involved is the study of liver and pancreatic function. Gastroesophageal Reflux Disease (GERD), ulcers, colonic polyps, hepatitis, pancreatitis, gallbladder and biliary tract disease, as well as Irritable Bowel Syndrome (IBS), constipation/diarrhea, Small Intestinal Bacterial Overgrowth (SIBO), and leaky gut are just a sampling of the many maladies covered by the gastroenterologist.