A GI doctor is a gastroenterologist, a doctor whose area of expertise is the digestive system. According to the American Gastroeneterological Society, the digestive system includes the intestines, liver, pancreas and gall bladder, which work to break down food and deliver nutrients to the rest of the body.
GI doctors diagnose and treat rare digestive disorders as well as more common conditions such as celiac disease, irritable bowel syndrome, inflammatory bowel disease, food intolerance, heartburn, GERD, viral hepatitis, appendicitis, cirrhosis and diverticulitis. A patient may see a GI doctor for such things as nutritional deficiencies, obesity, constipation, diarrhea, vomiting, burping and gas. A GI doctor may perform a colonoscopy to view the colon and large intestine with a video, according to the AGA, which can help the gastroenterologist diagnose colorectal cancer, polyps, inflammation or other diseases of the intestines. During an endoscopy, a video camera can be used to diagnose issues involving the upper digestive system, including problems with the stomach o r abdomen, such as pain or bleeding, ulcers or tumors, and difficulty swallowing. It can also be used to view the gallbladder and pancreas. According to the AGA, colonoscopies and endoscopies are the most common tests performed by gastroenterologists. More modern GI tests include swallowing a camera which takes images of the gastrointestinal tract.