HealthcareDiscovery.AI / Doctors / California / Fontana / Gastroenterology

Gastroenterology in Fontana, California

Data updated monthly · Last refresh September 2026

11 Gastroenterology providers practice in Fontana. Listings are drawn from federal public records and are not endorsements.

Gastroenterology providers in Fontana

Listed alphabetically. Payment figures come from the federal Open Payments program, which requires drug and device companies to report what they pay physicians for consulting, speaking, meals, travel and royalties. A disclosed payment is a financial relationship, not evidence of wrongdoing, and many totals reflect a single meal. Figures cover calendar year 2025.

Dr. Alexander Han, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-5000
Dr. Blanca Viramontes, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Daniel Seid, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. David Kestenbaum, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Eve Kirschner, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Nehali Patel, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-5000
Dr. Patricia Hsia, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Scott Marnoy, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Timothy Jenkins, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910
Dr. Timothy Mccarter, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-7830
Dr. Tommy Oei, MD
Fontana, CA · No drug or device payments recorded (2025) · (909) 427-3910

Conditions Gastroenterology providers in Fontana, California commonly treat

Patients often search by condition rather than specialty. These are conditions typically managed by Gastroenterology providers. Individual practices vary, so confirm with the provider before booking.

Common questions

How many Gastroenterology providers are in Fontana, California?

There are 11 Gastroenterology providers with active NPI records practicing in Fontana, according to federal NPPES data refreshed monthly.

What conditions do Gastroenterology providers in Fontana treat?

Gastroenterology providers in Fontana commonly treat acid reflux, IBS, Crohn disease, ulcerative colitis, celiac disease and related conditions. Individual practices vary, so confirm with the provider before booking.

Where does this data come from?

Provider records come from the federal NPPES registry and CMS Doctors and Clinicians files. Payment figures come from the CMS Open Payments program for calendar year 2025. The directory refreshes monthly.

All specialties in Fontana Gastroenterology across California

Sources: NPPES (CMS), Doctors and Clinicians national files, CMS Open Payments 2025. Updated monthly. Records are public federal data and are not verified credentials, licensure checks, or endorsements. This directory is informational and not medical advice. How we build this directory.