Gastroenterology, also known as gastrology, is a specialized medicinal field, concerned with the human digestive system. This branch focuses on the study, functioning and disorders affecting the stomach, esophagus, intestines, and many associated organs including the pancreas, liver, and gallbladder. It is perhaps considered one of the youngest disciplines among the subspecialties of internal medicine. As this branch is too broad, many doctors specialize in treating disorders of the digestive system.

Doctors of gastroenterology do not perform surgery to treat diseases, but they may be board certified to perform biopsies and endoscopic examinations. Gastroenterologists use endoscopy, ultrasound, blood and bodily fluids tests, and surgery to make a diagnosis. It is often possible to treat patients during endoscopy where necessary, by using the endoscope (a long, flexible tube inserted through the mouth into various digestive regions) to insert tools for removing stones and growths, destroying cysts, inserting a stent, injecting cancer medications, or inserting a nerve block.