What Is a Gastroenterologist?

A Specialist Trained in Digestive and Liver Disorders

Palpating the Abdomen
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A gastroenterologist is a type of physician who specializes in disorders of the digestive tract. This includes all of the organs that span the alimentary canal from the mouth to the anus as well as the liver.

Gastroenterologists must undergo training and certification in internal medicine before pursuing a subspecialty in gastroenterology. In addition to the study of digestive physiology and diseases, gastroenterologists are trained to perform procedures like endoscopy used in diagnosis and treatment.

A gastroenterologist may be the primary point of care for people with chronic or serious gastrointestinal (GI) diseases. In most cases, however, people would be referred to a gastroenterologist if a digestive problem is beyond the scope of practice of a family doctor, internist, or primary care physician.


Gastroenterology is the study of the function and diseases of the esophagus, stomach, small intestine, colon, rectum, pancreas, gallbladder, bile ducts, and liver. It involves an in-depth understanding of digestion, nutrient absorption, gastrointestinal motility, and the function of the liver in digestion.


The aim of the gastroenterologist is to identify and treat conditions affecting the normal function of the digestive tract, both common and uncommon. These include:

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), 60 to 70 million Americans are affected by a digestive disorder, resulting in over 21 million hospitalizations and 48 million doctor visits each year.


People are often referred to a gastroenterologist if the cause of a disorder cannot be found or there is an abnormal finding in a stool test or abdominal X-ray. Among some of the symptoms that may warrant an investigation by a gastroenterologist:

  • Abnormal stool color
  • Anal leakage
  • Bloody stools (hematochezia)
  • Chronic abdominal pain or cramping
  • Chronic constipation or diarrhea
  • Chronic heartburn and indigestion
  • Chronic nausea or vomiting
  • Difficulty swallowing (dysphagia)
  • Excessive bloating or gas
  • Loss of appetite
  • Loss of bowel control
  • Malnutrition
  • Pain when swallowing (odynophagia)
  • Rectal bleeding
  • Sudden changes in blood habit
  • Unexplained weight loss
  • Yellowing of the eyes and/or skin (jaundice)

Cancer Screening

In addition to treatment, you should get a colonoscopy every 10 years starting from the age of 50 to screen to for colon cancer. African Americans, who are at higher risk, should get screened starting at 45. Doing so can help detect cancer early when it is most easily treated. Other tests used to screen for colon cancer include a fecal occult blood test and sigmoidoscopy.

Procedural Expertise

A gastroenterologist's expertise extends from the evaluation and treatment of digestive disorders to the prevention of disease and the maintenance of good gastrointestinal health.


The diagnostic tools used by a gastroenterologist are extensive and include lab tests, radiologic studies, directing imaging tests, and tissue studies. Here are just some of the tools central to a gastroenterology practice:


The treatments a gastroenterologist may explore range from medications and lifestyle changes to surgery and organ transplantation. Some of these can be provided by the gastroenterologist; others may require a team of specialists, including surgeons, dietitians, and oncologists.


The list of drugs used to treat digestive disorders is extensive and may include antibiotics, antacids, antidiarrheals, proton pump inhibitors (PPIs), H2 blockers, and promotility agents like Reglan (metoclopramide). Over-the-counter medications like stool softeners, laxatives, fiber supplements, nonsteroidal anti-inflammatory drugs (NSAIDs), and hemorrhoid creams may also be prescribed.

Newer pharmaceutical medications often target specific components of the digestive tract or treat specific conditions. Examples include:

  • Aemcolo (rifamycin), used for relief of traveler's diarrhea
  • Entyvio (vedolizumab), used for ulcerative colitis and Crohn's disease
  • Keytruda (pembrolizumab), used for certain types of stomach, colon, or esophageal cancer
  • Onivyde (irinotecan liposome), used for metastatic pancreatic cancer
  • Opdivo (nivolumab), used for metastatic colorectal cancer
  • Symproic (naldemedine), used for opioid-induced constipation
  • Viberzi (eluxadoline), used for IBS with diarrhea
  • Viokace (pancrelipase), used for pancreatic insufficiency
  • Xerava (eravacycline), used to treat intra-abdominal infections
  • Zinplava (bezlotoxumab), used for recurrent Clostridium difficile infection


In addition to medications, various procedures may be used to manage or cure a digestive disorder. In some cases, all that may be needed are changes in diet or eating habits in tandem with weight loss, exercise, and smoking cessation.

More intensive treatments are sometimes required, particularly in cases of cancer, bowel perforation, or severe inflammatory bowel disease (IBD). Examples include:

  • Biliary stenting (used to unblock the bile duct)
  • Bowel resection (removal of a section of the bowel)
  • Colostomy (diversion of the bowel to an opening on the abdomen)
  • Gallstone or biliary stone removal (via ERCP or MRCP)
  • Hemorrhoidectomy (hemorrhoid removal)
  • Ileostomy (diversion of the ileum to an opening on the abdomen)
  • Intestinal transplant
  • Liver transplant
  • Polypectomy (removal of colon polyps via thermal ablation, electrocautery, etc.)
  • Proctectomy (surgical removal of the rectum)
  • Sphincterotomy (used for treating anal fissures)


Some gastroenterologists choose to specialize in specific disorders or organ symptom. One of the most common is hepatology, devoted to the study of the liver.

Hepatologists are not required to undergo specific certification exams. They typically embark on a one- and two-year fellowship after getting board certification in gastroenterology to broaden their exposure to liver diseases. 

Others will partake in fellowships and training in subspecialties such as inflammatory bowel diseases, colorectal cancer, gastrointestinal motility, interventional endoscopy, neurogastroenterology, pediatric gastroenterology, and transplant hepatology, among others.

Training and Certification

In terms of training and education, gastroenterologists will undergo a minimum of 13 years of classroom study and practical training before achieving board certification.

To become a gastroenterologist, you must first complete a four-year bachelor's degree followed by four years of medical school to obtain your doctor of medicine (MD) or doctor of osteopathic medicine (DO) degree. After certification, the next step would involve a three-year residency in internal medicine. It is during this time that you can elect to specialize in gastroenterology.

A gastroenterology fellowship lasts for two to three years, during which time you will learn how to evaluate patients with gastrointestinal complaints, treat a broad range of conditions, and provide recommendations to maintain health and prevent disease.

The fellowship training will be overseen one or several national societies, including the American Board of Internal Medicine (ABIM), the American College of Gastroenterology (ACG), the American Gastroenterological Association (AGA), or the American Society for Gastrointestinal Endoscopy (ASGE). 

Once you have successfully completed the fellowship training, you can obtain certification by passing the gastroenterology board exam administered by the ABIM.

Some gastroenterologists receive special recognition for extraordinary achievements in gastroenterology. Those afforded the honor are declared Fellows of the ACG or ACP and can denote it with the letters FACG or FACP after their names.

Appointment Tips

Meeting a gastroenterologist for the first time can be uncomfortable given that most people don't like to discuss things like bowel movements, gas, or diarrhea.

It is important not to let your discomfort get in the way of a diagnosis. The more accurately you describe your sympoms—including things like the consistency, smell, and color of stools—the sooner the doctor will know where to start the investigation.

If you have chronic symptoms, keep a journal outlining the time, date, duration, and specifics of each event. Be sure to write down what you were doing at the time of the event, including the foods you ate and whether you were stressed, lying down, or exercising strenuously.

Moreover, ask as many questions as you need to fully understand the procedures and what a test result may or may not mean. Examples include:

  • What do you suspect is causing my symptoms?
  • What tests can you use to confirm this?
  • What is involved in the test?
  • How long will it take to get the results?
  • What can I do in the meantime to control my symptoms?
  • Are there things I am doing that make my symptoms worse?
  • Is my condition something that needs to be managed, or can it be cured?

Before your appointment, check that the gastroenterologist office accepts your insurance. If they do, ask your primary care doctor to forwards all relevant medical records.

If a test is recommended, check to see if it is covered by your insurance and what your copay/coinsurance costs will be. If the out-of-pocket costs are too high, ask the gastroenterologist if there are any less costly alternatives. In some cases, the gastroenterologist may offer an upfront cash discount or an interest-free installment plan.

A Word From Verywell

When searching for a gastroenterologist, a professional referral is usually the best place to start. Ask your primary care physician for a list of local referrals. You can then check to see if they are on the in-network provider list of your insurance policy.

The ACG also provides an online locator to find board-certified specialists in your area. People searching for a hepatologist can use the ACG liver specialist locator.

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Article Sources
  • Greenberger, N.; Blumberg, R.; and Burakoff, R. (2011) Current Diagnosis and Treatment: Gastroenterology, Hepatology, and Endoscopy. New York, New York: McGraw Hill Professional.

  • National Institute of Diabetes and Digestive and Kidney Disorders. Digestive Diseases Statistics for the United States. Bethesda, Maryland: National Institutes of Health; updated November 2014.