MR
16 Years of Experience
Accepting patients
Affiliated with a Castle Connolly Top Hospital
Who is Dr. Ryou, Gastroenterologist in Boston, MA?
Dr. Marvin Ryou, MD is a Gastroenterologist, who primarily practices in Boston, MA. He has been practicing for over 16 years and is board certified. Dr. Ryou graduated from Harvard Medical School, Boston, Massachusetts and completed his residency at Brigham & Women'S Hosp, Internal Medicine. Dr. Ryou is fluent in English, and is currently seeing new patients. Dr. Ryou’s practice accepts Cigna, Medicaid, Medicare, UnitedHealthcare, Aetna and other major insurance plans. To book an appointment or to confirm insurance options, please call Dr. Ryou’s office at (617) 732-5500.
What are Areas of Expertise for Dr. Ryou?
Dr. Marvin Ryou, MD is a highly-rated, board-certified Gastroenterologist known for expertly diagnosing, treating, and managing a wide array of related conditions or procedures. Utilizing the latest medical advancements and evidence-based practices, Dr. Ryou empowers patients to confidently navigate their health journey, specializing in Bariatric Endoscopy , Endoscopic Hepatology, Endoscopic Ultrasound, Obesity, or comprehensive wellness support. Serving the Boston/MA community, Dr. Ryou is dedicated to enhancing lives through expert, patient-centered care.
Where did Dr. Ryou go to medical school and complete their residency?
Residency: Brigham & Women'S Hosp, Internal Medicine
Medical School: Harvard Medical School, Boston, Massachusetts | Harvard Medical School, Boston, Massachusetts
Is Dr. Ryou board certified as a Gastroenterologist?
Yes, Dr. Marvin Ryou, MD is board certified by the American Board of Internal Medicine
What languages does Dr. Ryou speak?
Dr. Ryou and their clinical team can communicate with patients in the following languages:
English
What conditions does Dr. Ryou treat?
As a Gastroenterologist, Dr. Ryou diagnoses, treats, and manages a wide range of conditions. This condition information is derived from anonymized insurance claims and highlights the medical conditions most commonly treated by Dr. Ryou. It provides insight into the doctor’s areas of experience and expertise based on real-world patient encounters from the past two years, updated quarterly.
Also known as:
- Difficulty Swallowing
- Swallowing Disorder
- Dysphagia
- Trouble swallowing
- Painful swallowing
ICD-10 Codes:
- R1310: Dysphagia, unspecified
Also known as:
- Stomach and Duodenum Disorder
- Stomach Disorder
- Gastric Conditions
- Duodenal Conditions
- Digestive System Disorders
ICD-10 Codes:
- K3189: Other diseases of stomach and duodenum
Also known as:
- After Surgery
- Digestive Disease
- Postoperative Digestive Disorders
- Other GI Complications Post-Op
- Problems After Digestive Procedure
ICD-10 Codes:
- K9189: Other postprocedural complications and disorders of digestive system
Also known as:
- Pancreatic Cyst
- Pancreatic Disease
- Cyst on Pancreas
- Pancreatic Pseudocyst
- Fluid Sac on Pancreas
ICD-10 Codes:
- K862: Cyst of pancreas
Also known as:
- Gastrointestinal Device Fitting and Adjustment
- GI Appliance Fitting
- Digestive Device Adjustment
- Enteral Device Care
ICD-10 Codes:
- Z4659: Encounter for fitting and adjustment of other gastrointestinal appliance and device
Also known as:
- Colon Cancer Screening
- Health Screening
- Colorectal Cancer Screening (PDQ®)
- Screening Tests to Detect Colorectal Cancer and Polyps
- Tests to Detect Colorectal Cancer and Polyps
- Colorectal Cancer Screening
- Colonoscopy Screening
- Bowel Cancer Screening
ICD-10 Codes:
- Z1211: Encounter for screening for malignant neoplasm of colon
Also known as:
- Blocked Esophagus
- Esophagus Disorder
- Esophageal Obstruction
- Food Pipe Blockage
- Swallowing Difficulty
ICD-10 Codes:
- K222: Esophageal obstruction
What procedures does Dr. Ryou perform?
As a Gastroenterologist, Dr. Ryou performs a variety of medical procedures. This procedure information is derived from anonymized insurance claims and highlights the medical procedures most commonly performed by Dr. Ryou. It provides insight into the doctor’s areas of experience and expertise based on real-world patient encounters from the past two years, updated quarterly.
Also known as:
- EGD with Esophageal Balloon Dilation
- Diagnostic Upper Endoscopy with Biopsy
- EGD with Endoscopic Ultrasound
- Upper Endoscopy with Injections
- Upper Endoscopy with Esophageal Dilation
- Flexible Esophagoscopy with Balloon
- EGD with Balloon Widening
- EGD with Biopsy
- Esophagogastroduodenoscopy
- Upper GI Endoscopy
- Stomach Scope with Sample
- Upper GI Endoscopy with Ultrasound
- EUS (Endoscopic Ultrasound)
- Esophagus, Stomach, Duodenum Ultrasound
- EGD with Submucosal Injections
- Esophagogastroduodenoscopy with Injections
- Stomach Scope with Medication
CPT Codes:
- 43249: Esophagogastroduodenoscopy, flexible, transoral; with transendoscopic balloon dilation of esophagus (less than 30 mm diameter)
- 43235: Esophagogastroduodenoscopy, flexible, transoral; diagnostic, including collection of specimen(s) by brushing or washing, when performed (separate procedure)
- 43237: Esophagogastroduodenoscopy, flexible, transoral; with endoscopic ultrasound examination limited to the esophagus, stomach or duodenum, and adjacent structures
- 43236: Esophagogastroduodenoscopy, flexible, transoral; with directed submucosal injection(s), any substance
Also known as:
- Upper Endoscopy with Stomach/Duodenum Dilation
- Upper Endoscopy with Ultrasound (EUS)
- EGD with Dilation
- Esophageal Dilation
- Stomach Stricture Widening
- Duodenal Stricture Repair
- EGD with endoscopic ultrasound
- Esophageal ultrasound
- Stomach ultrasound endoscopy
- Duodenal ultrasound endoscopy
CPT Codes:
- 43245: Esophagogastroduodenoscopy, flexible, transoral; with dilation of gastric/duodenal stricture(s) (eg, balloon, bougie)
- 43259: Esophagogastroduodenoscopy, flexible, transoral; with endoscopic ultrasound examination, including the esophagus, stomach, and either the duodenum or a surgically altered stomach where the jejunum is examined distal to the anastomosis
Also known as:
- Upper Endoscopy with Biopsy
- Biopsy
- Endoscopy
- EGD with Biopsy
- Gastroscopy with Biopsy
- Esophagogastroduodenoscopy with Biopsy
CPT Codes:
- 43239: Esophagogastroduodenoscopy, flexible, transoral; with biopsy, single or multiple
Also known as:
- Upper Endoscopy for Foreign Body Removal
- EGD for Foreign Body
- Gastroscopy for Object Removal
- Esophagogastroduodenoscopy for Foreign Body
CPT Codes:
- 43247: Esophagogastroduodenoscopy, flexible, transoral; with removal of foreign body(s)
Also known as:
- Upper GI Scope with Stent Placement
- EGD with Stent
- Esophageal Stent Placement
- Stomach Stent Insertion
CPT Codes:
- 43266: Esophagogastroduodenoscopy, flexible, transoral; with placement of endoscopic stent (includes pre- and post-dilation and guide wire passage, when performed)
Also known as:
- Upper GI Endoscopy with Ultrasound Biopsy
- Biopsy
- Endoscopy
- Ultrasound
- EGD with EUS-FNA
- Endoscopic Ultrasound Biopsy
- Esophageal/Stomach Biopsy
CPT Codes:
- 43238: Esophagogastroduodenoscopy, flexible, transoral; with transendoscopic ultrasound-guided intramural or transmural fine needle aspiration/biopsy(s), (includes endoscopic ultrasound examination limited to the esophagus, stomach or duodenum, and adjacent structures)
Also known as:
- Colonoscopy with Biopsy
- Colonoscopy with Polyp Removal
- Colonoscopy
- Colorectal Cancer Screening Tests
- Flexible Colonoscopy
- Colon Biopsy
- Large Intestine Scope
- Colorectal Cancer Screening
- Flexible Colonoscopy with Polypectomy
- Colon Polyp Removal
- Colorectal Lesion Excision
CPT Codes:
- 45380: Colonoscopy, flexible; with biopsy, single or multiple
- 45385: Colonoscopy, flexible; with removal of tumor(s), polyp(s), or other lesion(s) by snare technique
Also known as:
- Upper Endoscopy with Ultrasound and Biopsy
- Biopsy
- Endoscopy
- Ultrasound
- EGD with Endoscopic Ultrasound Biopsy
- Transoral EUS-FNA
- Esophagogastroduodenoscopy with Biopsy
CPT Codes:
- 43242: Esophagogastroduodenoscopy, flexible, transoral; with transendoscopic ultrasound-guided intramural or transmural fine needle aspiration/biopsy(s) (includes endoscopic ultrasound examination of the esophagus, stomach, and either the duodenum or a surgically altered stomach where the jejunum is examined distal to the anastomosis)
Also known as:
- ERCP with Gallstone Removal
- ERCP
- Endoscopic Gallstone Removal
- Biliary Duct Stone Removal
- Pancreatic Duct Cleaning
CPT Codes:
- 43264: Endoscopic retrograde cholangiopancreatography (ERCP); with removal of calculi/debris from biliary/pancreatic duct(s)
Does Dr. Ryou accept my insurance?
Dr. Ryou accepts most major insurance plans. Important: Please call our office at (617) 732-5500 before your appointment to verify that your specific plan and network are accepted.
What insurance plans does Dr. Ryou accept in Boston, MA?
Dr. Ryou in Boston, MA accepts plans from many carriers. While this list is updated regularly, it is not a guarantee of coverage.
Top Insurances
BCBS Unspecified
Blue Cross Blue Shield of Massachusetts
Federal Employee Program
Health Pointe
Medicaid
Medicare
Point32Health
State of Nevada
State of Tennessee
UnitedHealthcare
View All Insurances
Where is Dr. Ryou's office located?
Recognitions
Castle Connolly Doctor’s Choice Awards
Doctor’s Choice - 2025
Among the most nominated for the Castle Connolly Top Doctor recognition in 2025
What is Dr. Ryou's NPI number?An National Provider Identifier (NPI) is a unique ID number that identifies doctors and healthcare providers nationwide.
Dr. Ryou's National Provider Identifier (NPI) number is 1821104787.
What common questions do patients ask about Dr. Ryou?
Here are answers to patients Frequently Asked Questions (FAQ’s) about Dr. Ryou
What is Dr. Marvin Ryou's specialty?
Dr. Ryou is a Gastroenterologist near Boston, MA. An internist focused on diagnosing and treating disorders of the digestive system, encompassing the stomach, intestines, liver, and gallbladder. This specialist manages conditions like abdominal pain, ulcers, diarrhea, cancer, and jaundice, and performs intricate diagnostic and therapeutic procedures using endoscopes to examine internal organs. Contact Dr. Ryou to book an appointment today.
Is this Dr. Marvin Ryou affiliated with a ranked Castle Connolly Top Hospital?
Yes, Dr. Ryou is affiliated with Brigham and Women's Hospital which is a Castle Connolly Top Hospital. Castle Connolly Top Hospitals are healthcare institutions recognized for their excellence in specific medical procedures and overall patient care. They are identified through a rigorous peer nomination process, evaluating factors like patient outcomes, quality of care, and expertise. The list recognizes hospitals that excel in 20 or more specific medical procedures, representing the top 25% nationwide. Castle Connolly Top Hospitals
Where can I learn more about Gastroenterologist?
Explore Gastroenterologist with insights from trusted medical experts on EverydayHealth.com, where you'll find the most relevant content and helpful condition guides for up-to date information about symptoms, causes, diagnosis, treatment and more. See all our health guides to find trusted information on medical conditions from our experts at Everyday Health.
Is Marvin Ryou accepting new patients in Boston, MA?
Yes, Dr. Marvin Ryou is accepting new patients at this time.
Does Dr. Marvin Ryou offer online booking?
Please contact Dr. Ryou's office at (617) 732-5500 for information about online booking, telehealth, or to schedule an appointment.
How can I make an appointment with Marvin Ryou?
Please contact Dr. Ryou's office at (617) 732-5500 for information regarding telehealth appointment availability or for scheduling assistance.
Which board certifications does Dr. Marvin Ryou have?
Dr. Marvin Ryou is certified by the American Board of Internal Medicine.
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