Aaron B. Greenspan, MD
Gastroenterology
- Address
- 1 Barnes Jewish Hospital Plz, St. Louis 63110
- Telehealth
- Not listed
- Medicare
- Not listed
- Medicaid
- Not listed
Last verified Oct 2026 Report a correction

230 listed in St. Louis, MO · Listings last verified October 2026 · How we vet listings
We list 230 gastroenterologists in the St. Louis area, most of them in St. Louis, Chesterfield and St. Peters. All are physicians (MD or DO), shown with the practice's phone number, address and Google rating where we could match one. 12 practices say they offer telehealth visits. Use the filters to narrow by city, telehealth, Medicare or Medicaid.
Gastroenterology
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Gastroenterology
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Gastroenterology
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Gastroenterology
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Gastroenterology
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Gastroenterology
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Gastroenterology
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Gastroenterology
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Specialists in Gastroenterology
Gastroenterology
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Gastroenterology
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Gastroenterology
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SSM Health Medical Group
Gastroenterology
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Gastroenterology
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Gastroenterology
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Gastroenterology
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Gastroenterology
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BJC Medical Group at Progress West - Specialists
Gastroenterology
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Gastroenterology
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BJC Medical Group Gastroenterology at Missouri Baptist Medical Center
Gastroenterology
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Gastroenterology
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Our St. Louis listings cover the Missouri side of the metro: St. Louis County, St. Louis City, St. Charles County, Jefferson County, Franklin County and Lincoln County. Providers on the Illinois side, such as Belleville, Edwardsville and Alton, are listed under the Belleville–Metro East area.
Specialist care here is concentrated in a few large health systems: BJC HealthCare with Barnes-Jewish Hospital and Washington University physicians, Mercy, SSM Health and St. Luke's Hospital in Chesterfield. Each has clinics well beyond its main campus, so the same practice may have offices in the city, west St. Louis County and St. Charles County. Independent specialty groups practice alongside them, especially in Creve Coeur, Chesterfield and along the I-70 corridor in St. Peters, O'Fallon and Wentzville.
Most listings are in the City of St. Louis and St. Louis County, with a growing share in St. Charles County. If you live in Jefferson or Franklin County, check Festus and Washington before driving into the city.
Gastroenterologists here practice mainly through Washington University, Mercy, SSM Health and St. Luke's, plus independent GI groups in west county and St. Charles County. Many practices run their own endoscopy centers, so ask where your colonoscopy would be done.
Nearby: Belleville–Metro East, IL · Columbia–Jefferson City, MO · Cape Girardeau, MO
A gastroenterologist, or GI doctor, diagnoses and treats problems of the digestive tract: the esophagus, stomach, intestines, colon, liver, pancreas and gallbladder. People see one for heartburn that won't go away, ongoing belly pain, diarrhea or constipation, bleeding, Crohn's disease or ulcerative colitis, and for colonoscopies.
Start with the kind of care you need. Many GI doctors handle a wide range of problems, but some focus on one area:
If you're not sure, a general gastroenterologist is the right first stop. They'll refer you on if you need a subspecialist.
Check credentials. Board certification in gastroenterology shows a doctor has finished specialty training and passed a certification exam. You can look up any doctor's certification for free on the American Board of Internal Medicine website [1]. Our listings show the credentials doctors report in the federal NPI registry, but we don't verify board certification.
Know if you're due for a colonoscopy. Experts recommend colorectal cancer screening for adults ages 45 to 75 [2]. A colonoscopy is one option. Some people can start with a stool test instead. Ask your primary care doctor which test fits you, and whether your family history means you should start earlier.
Confirm insurance before you book. Practices change the plans they accept, so call the office or check your insurer's directory. HMO plans usually need a referral first. Medicare Part B covers medically necessary specialist visits; you typically pay 20% of the Medicare-approved amount after your deductible [5].
Ask where procedures are done. Colonoscopies and other scopes happen in a hospital or a separate endoscopy center. The location can change what you pay, so ask before you schedule.
Know when not to wait. Vomiting blood or material that looks like coffee grounds, black or tar-like stool, or feeling faint, confused or cold and clammy with belly symptoms need emergency care, not an appointment [4]. Call 911.
It depends on your insurance. Most HMO plans require a referral from your primary care doctor before they'll cover a specialist visit. PPO plans and traditional Medicare usually don't. Some GI practices also want a referral or recent test results before they book you, especially for a procedure, so call ahead and ask what to bring.
The U.S. Preventive Services Task Force recommends colorectal cancer screening for adults ages 45 to 75. A colonoscopy is one way to screen, and stool tests are another. People with a family history of colon cancer, certain polyps or inflammatory bowel disease may need to start earlier or screen more often. Ask your doctor what's right for you.
Yes. Medicare Part B covers a screening colonoscopy once every 120 months for most people, or once every 24 months if you're at high risk. There's no minimum age. You pay nothing for the screening if your doctor accepts assignment. If a polyp is removed during the test, you may owe a share of the cost.
Expect questions about your symptoms, diet, bowel habits, medications and family history, plus a physical exam. The doctor may order blood work, a stool test, imaging or a scope procedure such as an upper endoscopy or colonoscopy. Bring a list of your medications and any recent lab results, scans or procedure reports.
Look the doctor up on the American Board of Internal Medicine's free "Verify a Physician" tool, which shows whether they're certified in gastroenterology. Our listings show the credentials doctors report to the NPI registry, but we don't verify certification ourselves.