A gastroenterologist is a doctor who specializes in diagnosing and treating problems anywhere in your digestive system. That covers more territory than most people realize: not just the stomach and intestines, but also the esophagus, liver, pancreas, gallbladder, and bile ducts. These physicians complete about 14 years of education and training before practicing independently, making them among the most extensively trained specialists in medicine.
What a Gastroenterologist Treats
Your digestive system starts at your mouth and extends through a long chain of organs, each with its own set of things that can go wrong. Gastroenterologists handle the full range. The most common conditions they manage include gastroesophageal reflux disease (GERD), inflammatory bowel disease (IBD, which includes Crohn’s disease and ulcerative colitis), celiac disease, and various forms of hepatitis. They also evaluate unexplained abdominal pain, swallowing difficulties, chronic diarrhea or constipation, and abnormal liver function.
Because the liver, pancreas, and gallbladder all play direct roles in digestion, these organs fall squarely within a gastroenterologist’s expertise. If you have gallstones, fatty liver disease, or pancreatitis, a gastroenterologist is typically the specialist coordinating your care.
Training and Education
Becoming a gastroenterologist takes a minimum of 14 years after high school: four years of college, four years of medical school, three years of internal medicine residency, and three years of gastroenterology fellowship. By the time they see their first patient independently, they’ve spent a decade in post-college training. They must also be board eligible or board certified in internal medicine before starting their fellowship.
Some gastroenterologists pursue even further specialization. A one-year transplant hepatology fellowship focuses specifically on liver transplant care. An advanced endoscopy fellowship, also an additional year, trains physicians in complex procedures like endoscopic ultrasound and specialized techniques for the bile ducts and pancreas. These fourth-year fellowships are optional but common among gastroenterologists working at academic medical centers.
Common Procedures
Gastroenterologists are best known for two procedures: upper endoscopy and colonoscopy. During an upper endoscopy, a thin, flexible camera is passed through your mouth to examine the esophagus, stomach, and the first part of the small intestine. During a colonoscopy, a similar camera enters through the rectum to view the entire colon. Both allow the doctor to take small tissue samples (biopsies) and remove abnormal growths like polyps during the same session. Small polyps under 5 mm can be removed with a biopsy tool, while larger ones require a technique called polypectomy.
These aren’t just diagnostic tools. A gastroenterologist can stop bleeding, stretch a narrowed section of the esophagus, or remove precancerous tissue during the same procedure. Endoscopic retrograde cholangiopancreatography (ERCP) is a more specialized procedure that lets them access the bile ducts and pancreatic duct to remove stones or place stents.
For patients who can’t tolerate or prefer to avoid traditional endoscopy, capsule endoscopy is an alternative for certain situations. You swallow a pill-sized camera that takes thousands of images as it passes through your digestive tract. It’s painless, requires no sedation, and is particularly useful for examining the small bowel, a section of the gut that standard scopes can’t easily reach. The tradeoff is that the capsule can’t take biopsies or remove polyps, so if it finds something, you may still need a conventional procedure.
Colorectal Cancer Screening
One of the most important reasons people see a gastroenterologist is for colorectal cancer screening. The U.S. Preventive Services Task Force recommends that average-risk adults start screening at age 45. For people between 50 and 75, screening carries the task force’s strongest recommendation. “Average risk” means you have no personal history of colorectal cancer, adenomatous polyps, or inflammatory bowel disease, and no family history of genetic conditions like Lynch syndrome that raise your lifetime cancer risk.
Colonoscopy remains the gold standard because it can both detect and remove precancerous polyps in a single visit. If your results are normal, most people won’t need another for 10 years. Stool-based tests are also available for those who prefer a less invasive option, though a positive result still requires a follow-up colonoscopy.
How They Differ From Colorectal Surgeons
People sometimes confuse gastroenterologists with proctologists, now more commonly called colorectal surgeons. The key difference is scope and approach. Gastroenterologists cover the entire digestive system and primarily use nonsurgical methods: medications, endoscopic procedures, and ongoing disease management. Colorectal surgeons focus specifically on the colon, rectum, and anus, and they’re trained to perform open and minimally invasive surgeries like hemorrhoid removal, fistula repair, and rectal prolapse correction.
There’s some overlap. Both perform colonoscopies, for example. But if you need surgery on your colon or rectum, that’s a colorectal surgeon’s territory. If you need long-term management of a condition like Crohn’s disease or a procedure on your bile ducts, that’s a gastroenterologist.
Signs You May Need One
Most people are referred to a gastroenterologist by their primary care doctor, but knowing which symptoms warrant a specialist visit can help you advocate for yourself. Rectal bleeding, chronic abdominal pain, persistent diarrhea (especially if it wakes you at night), and unexplained weight loss are all considered major reasons for referral. A perianal fistula or abscess also warrants prompt evaluation.
Less urgent but still worth discussing with your doctor: ongoing heartburn that doesn’t respond to over-the-counter medications, difficulty swallowing, chronic bloating, or a family history of colon cancer or IBD. These don’t always require a specialist, but a gastroenterologist can run targeted tests your primary care doctor may not have access to.
Access and Availability
Getting an appointment with a gastroenterologist can be straightforward or difficult depending on where you live. A 2025 analysis found significant geographic disparities in the United States. Metropolitan areas had roughly adequate supply, but non-metropolitan areas had only about 30% of the gastroenterologists needed relative to demand. Regionally, the South had the lowest availability and the Northeast the highest. If you’re in a rural area or underserved region, wait times for a non-urgent appointment can stretch to several months, making it especially important to get a referral early when symptoms first appear rather than waiting for them to worsen.