★★★★★
- Accepting New Patients
Dr. Mark Tsuchiyose
Gastroenterology, Hepatology & Internal Medicine
Board-Certified Gastroenterologist and Hepatologist with over 35 years of experience providing compassionate, patient-centered and innovative care in the San Francisco Bay Area.
About Dr. Tsuchiyose
Dr. Mark M. Tsuchiyose has provided comprehensive GI and Liver care including a wide range of digestive and liver disorders with a personalized, patient-centered approach. His extensive training in diagnostic and therapeutic endoscopy allows him to find the best clinical outcome.
He has further honed his practice by adding formal training and clinical experience in functional and integrative medicine since 2014 when his daughter failed to improve from her post-IBS and Lyme disease diagnoses despite visits to multiple specialists.
Understanding the functional disorder of the pyloric valve has resulted in his use of supplements improving bile injury allowing his patients to get off Proton Pump Inhibitors with their known long term side effects.
This same drive to think out of the box has led him to significantly reduce fat in the liver in 90% of his patients at his new CDCH clinic tackling the Metabolic Syndrome. Besides focusing on the individual patient, Dr. Tsuchiyose has always advocated for his fellow physicians, community and the public’s health.
- Over 35 years of clinical experience in gastroenterology and hepatology
- Performed thousands of diagnostic and therapeutic endoscopic procedures
- Consistent Adenoma Detection Rate on par with the national average
- Assistant Clinical Professor of Medicine UCSF, San Francisco, CA (1996-2006)
- Chief of Gastroenterology of Seton Medical Center, Daly City, CA (2002-2009)
- Chairman of Internal Medicine at Seton Medical Center, Daly City, CA (2009-2013)
- Vice-Chief of Staff Seton Medical Center, Daly City, CA (7/2022-6/2024)
- Chief of Staff Seton Medical Center, Daly City, CA (7/2024-present)
- Vice-President of Clinical Affairs, Therapeutic Lead, GI, Adaptive Research (2021-2024)
- Medical Director of the Seton Nutritional Support Team, Daly City, CA (1997-2000)
Positions to Help Other Physicians
- President of Pacific Specialists Medical Group (1998-1999) - to combat unfair HMO practices
- President of Gastroenterology Specialty Network (1999-2000) - to combat unfair practices of all insurances and HMOs
Positions to Help Other Physicians
- Board Member of the Seton Foundation (2005-2008)
- Participated throughout the years with the Hep B free program
Commitment to Public Health
- Founder of the Center for Diabetes and Cardiometabolic Health at AHMC Seton Medical Center to combat the current epidemic of chronic disease
- Member of the research committee for Seton Medical Center (2022-Present)
We accept most major insurance plans. Please contact our office to verify coverage for your specific plan.
Accepted Insurance Plans:
- Medicare
- Blue Cross Blue Shield
- Aetna
- Cigna
- United Healthcare
Additional Plans:
- Brown and Toland
- Hills Physician
- Health Net
- Anthem
- And many more...
Please call (650) 993-6629 to verify your insurance coverage before your appointment.
Professional Training & Credentials
Dr. Tsuchiyose brings decades of specialized training and recognized expertise in gastroenterology, hepatology, and internal medicine.
Medical School
University of Southern California
Doctor of Medicine, 1983
Internship
LAC/USC Medical Center
1983-1984
Residency - Internal Medicine
Huntington Memorial Hospital
1984-1986
Fellowship - Hepatology
Huntington Memorial Hospital
1986-1987
Fellowship - Gastroenterology
LAC/USC
1987-1989
Advanced ERCP Training
Holland & Japan
International Training, 1989
Professional Recognition
Board Certified in Internal Medicine
Board Certified in Gastroenterology
Board Certified in Hepatology
Fellow, American College of Gastroenterology
Member, American Gastroenterological Association
Chief of Staff, Seton Medical Center (Current)
Areas of Expertise
Comprehensive digestive health care with specialized expertise in advanced endoscopic procedures, liver disease management, and functional GI medicine.
- Diagnostic and Therapeutic Endoscopy with expanded understanding of physiology to tailor personalized care
- Colonoscopy and Colon Cancer Screening with high ADR
- Acid reflux & GERD treatment with the understanding of bile gastritis and esophagitis and the unique proven protocol to manage this difficult subset of GERD patients
- All liver disease management including hepatitis B & C with particular interest and success with all fatty liver (MAFLD & MASH)
- ERCP (Endoscopic Retrograde Cholangiopancreatography)
- Pancreatic & Biliary Disorders
Dr. Tsuchiyose specializes in functional GI medicine to treat a wide range of digestive symptoms:
Research & Publications
Dr. Tsuchiyose has contributed to advancing medical knowledge through research and peer-reviewed publications throughout his career.
- Numerous retrospective comparative studies of liver diseases with R. Peters, MD (1975-1977)
- USC Liver Unit, electron microscopic characteristics of NANB Viral liver infections in chimpanzees and trace element spectrophotometry characteristics liver diseases with R. Peters, MD (1977-1979)
- H. Edmonston, MD. Data collection for AFIP Liver fascicle on cholangiocarcinoma (1980)
- Department of Obstetrics and Gynecology, physiologic changes of hot flushes (1985)
- Cornelius Dooley, MD, Campylobacter pylori in Barrett's esophagus (1988)
- Hepatitis B eradication of the virus and CCC component (present)
- Collaboration with Genentech to reduce fibrosis in the setting of MASH (1/2026)
- J. Weissman, MD, M. Tsuchiyose, R. Peters, MD, "Lack of response to recombinant Hepatitis B Vaccine in non-responders to the plasma vaccine". JAMA September, 1988 - 260:12, 23-30
- A. George, M. Tsuchiyose, C. P. Dooley "Sensitivity of the gastric mucosa to acid and duodenal contents in patients with non-ulcer dyspepsia", Neurology, July, 1986 - 101: 1, 3-6
- S. Stain, H. Cohen, M. Tsuchiyose, A. Donovan "Choledocholithiasis endoscopic sphincterotomy or common bile duct duration" Annals of Surgery, June, 1991 - 627-634
- M. Tsuchiyose, M. J. Tong, MD, T. Merrigan "Pulse prednisone and interferon in hepatitis B chronic active hepatitis"
- E. A. Tsuchiyose, Anupam Aditi, MD, K. Tsuchiyose, MS, M. Tsuchiyose, MD. Abstract presented at ACG, "Adenoma Detection Rate found to be independent of time of day in single site sample using individual endoscopists". October, 2017
- The effect of fatigue on ADR - Erika Tsuchiyose et al
- The positive effects of liver supplements on reduction of fatty liver, a single site's 6 months data. To be submitted to the 2026 American College of Gastroenterology national conference