Summary

Dr. John Lah is a gastroenterologist and internal medicine physician with 26 years of experience treating digestive health conditions. He earned his medical degree from New York Medical College and has built his career focusing on comprehensive gastrointestinal care. Dr. Lah speaks both Spanish and English, allowing him to serve a diverse patient population.

Dr. Lah practices at multiple locations throughout California, including Whittier, Downey, Fountain Valley, Los Alamitos, Huntington Beach, Irvine, and Orange. His hospital affiliations include PIH Health Hospital Whittier, UCI Health Los Alamitos, Downey Regional Medical Center, and Orange Coast Memorial Medical Center. He specializes in treating colon polyps, hemorrhoids, and diverticular disease. Dr. Lah performs colonoscopies and both upper and lower gastrointestinal endoscopies to diagnose and treat various digestive disorders.

Overview based on verified provider data

Quick Facts

  • accepting new patients
  • 2.3
  • 26 years of experience
  • speaks Spanish, English
  • New York Medical College
  • 3 written reviews
  • 2 specialties
  • 11 areas of expertise
  • 2 board certifications
  • 4 hospital affiliations
  • 11 office locations
  • Male

Office Locations

Dr. John Joon Lah has 11 locations

Pih Health Digestive Health Services

12291 Washington Blvd Ste 201Whittier, CA 90606
Mon8:00 am - 5:00 pm
Tue8:00 am - 5:00 pm
Wed8:00 am - 5:00 pm
Thu8:00 am - 5:00 pm
Fri8:00 am - 5:00 pm
SatClosed
SunClosed

Downey Regional Medical Center

11500 Brookshire AveDowney, CA 90241

Pih Health Hospital Whittier

12401 Washington BlvdWhittier, CA 90602

Uci Health Fountain Valley

17100 Euclid StFountain Valley, CA 92708

Uci Health Los Alamitos

3751 Katella AveLos Alamitos, CA 90720

Orange Coast Memorial Medical Center

9920 Talbert AveFountain Valley, CA 92708

United Gastroenterologists

18111 Brookhurst St Ste 5200Fountain Valley, CA 92708
Mon8:00 am - 5:00 pm
Tue8:00 am - 5:00 pm
Wed8:00 am - 5:00 pm
Thu8:00 am - 5:00 pm
Fri8:00 am - 5:00 pm
SatClosed
SunClosed

United Gastroenterologists

19582 Beach Blvd Ste 218Huntington Beach, CA 92648
Mon8:30 am - 5:00 pm
Tue8:30 am - 5:00 pm
Wed8:30 am - 5:00 pm
Thu8:30 am - 5:00 pm
Fri8:30 am - 5:00 pm
SatClosed
SunClosed

Huntington Beach Hospital

17772 Beach BlvdHuntington Beach, CA 92647

United Surgery Center Irvine

15825 Laguna Canyon Rd Ste 100Irvine, CA 92618
Mon7:00 am - 3:30 pm
Tue7:00 am - 3:30 pm
Wed7:00 am - 3:30 pm
Thu7:00 am - 3:30 pm
Fri7:00 am - 3:30 pm
SatClosed
SunClosed

United Surgery Center Orange

1140 W LA VETA AVE STE 550ORANGE, CA 92868
Mon8:00 am - 5:00 pm
Tue8:00 am - 5:00 pm
Wed8:00 am - 5:00 pm
Thu8:00 am - 5:00 pm
Fri8:00 am - 5:00 pm
SatClosed
SunClosed

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Dr. John Joon Lah, MD
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Dr. John Joon Lah, MDAshley Anderson, APRNRachel Oliver, APRNChimdi Mfebe, APRN
GastroenterologyGastroenterologyGastroenterologyGastroenterology
Accepts New Patients Accepts New Patients Accepts New Patients Accepts New Patients
2.3 
26 Years of Experience
No Virtual Visit Option Virtual Visit Available Virtual Visit Available Virtual Visit Available
Speaks Spanish, English Speaks English Speaks English Speaks English
Whittier , CASACRAMENTO , CASACRAMENTO , CALittle Rock , AR
Med School: New York Medical College Med School: East Tennessee State University - Quillen College of Medicine Med School: University of South Alabama Med School: Chamberlain University College of Nursing
Current Profile
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Insurance Plans Accepted by Dr. John Joon Lah

  • Accepts Medicare
  • Accepts Medicaid

Medical Specialties

Dr. John Joon Lah has the following 2 specialties

Specialty Expertise

Dr. John Joon Lah has the following 11 areas of expertise

  • Abdominal Pain
  • Acid Reflux Disease (Gastroesophageal Reflux / GERD)
  • Acid Reflux Disease (GERD)
  • Celiac Disease
  • Colonoscopy
  • Constipation
  • Hemorrhoids
  • Hepatitis C
  • Internal Medicine
  • Irritable Bowel Syndrome (IBS)
  • Ulcerative Colitis

Certifications, License, & Education

26 Years Experience

MEDICAL LICENSE

Medical Doctor, California, 2026, Active

EDUCATION & TRAINING

Medical School

New York Medical CollegeGraduated in 2000

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Frequently Asked Questions

Is Dr. John Lah accepting new patients?
Dr. John Lah is accepting new patients on Vitals. View Dr. John Lah's profile on Vitals to make an appointment.
Does Dr. John Lah accept my insurance?
You can see the insurance plans that Dr. John Lah accepts on their Vitals profile.
How can I make an appointment with Dr. John Lah?
You can find contact information for Dr. John Lah here on Vitals.
Does Dr. John Lah accept virtual/telehealth appointments?
Dr. John Lah has not indicated that they accept virtual/teleheatlh appointments. Contact their office through their Vitals profile to check for availability.
Which hospitals is Dr. John Lah affiliated with?
Dr. John Lah is affiliated with Pih Health Hospital Whittier, Uci Health Los Alamitos, Downey Regional Medical Center, and Orange Coast Memorial Medical Center.

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