Unio Specialty Care – Gastroenterology – Los Alamitos

Name: Unio Specialty Care
Address: Unio Specialty Care

Office Hours

Monday

8:30am - 4:30pm

Tuesday

8:30am - 4:30pm

Wednesday

8:30am - 4:30pm

Thursday

8:30am - 4:30pm

Friday

8:30am - 4:30pm

Saturday

Closed

Sunday

Closed

Office Hours

Monday

8:30am - 4:30pm

Tuesday

8:30am - 4:30pm

Wednesday

8:30am - 4:30pm

Thursday

8:30am - 4:30pm

Friday

8:30am - 4:30pm

Saturday

Closed

Sunday

Closed

Lisa Hertz, MD

Unio Specialty Care – Gastroenterology – Los Alamitos welcomes Dr. Lisa Hertz! Dr. Hertz is board certified in both Internal Medicine and Gastroenterology. She has been in private practice in the Long Beach/Los Alamitos area since 1989 and has extensive experience in treating a wide range of gastrointestinal illnesses with a focus on promoting thorough and complete healing through personal, intuitive and research-based care.

Lien Nguyen, NP

Unio Specialty Care – Gastroenterology – Los Alamitos welcomes Lien Nguyen, NP! Lien is a board-certified Nurse Practitioner who has been providing care to patients since 2004.

Meet Our Providers

Alaa Abousaif, MD

Ousama Alkhatib, MD

Hardeep M. Singh, MD

James J. Lee, MD

Haig Najarian, MD

Daniel Chiu, NP

Terri Rembuskos, PA-C

Connie Lin, NP

Lisa Hertz, MD

Lien Nguyen, NP

Reviews

Expert Gastroenterology Services in Los Alamitos

At Unio Specialty Care – Gastroenterology in Los Alamitos, we are proud to provide comprehensive digestive health care to patients across Los Alamitos and Orange County. Our board-certified gastroenterologists specialize in diagnosing, treating, and managing a wide range of gastrointestinal (GI) and liver conditions. Whether you need relief from acid reflux, evaluation for abdominal pain, or preventative screening for colon cancer, our team is here to support your health and well-being.

Patients choose us because we combine advanced diagnostic tools, compassionate care, and evidence-based treatments to deliver personalized solutions. Our services include colonoscopy, upper endoscopy (EGD), capsule endoscopy, flexible sigmoidoscopy, liver testing, hemorrhoid treatment, and nutrition counseling.

We welcome new patients for colon cancer screening, which is recommended starting at age 45, or earlier if you have a family history of colorectal cancer or other risk factors. Our team provides detailed preparation instructions and ensures a safe, comfortable experience throughout your procedure.

FAQs

Do I need a referral to see the gastroenterologist? ▼

It depends on your insurance plan. Some plans require a referral from your primary care doctor, while others do not. We’re happy to check for you when you call to schedule.

What conditions do you treat? ▼

We treat a wide range of digestive issues, including acid reflux, IBS, Crohn’s disease, ulcerative colitis, constipation, diarrhea, abdominal pain, and screening for colon cancer.

Is the visit covered by my insurance? ▼

Most GI visits are covered by insurance, but coverage can vary by provider and plan. We’ll verify your benefits and let you know about any expected costs before your appointment.

How should I prepare for my first appointment? ▼

No special preparation is usually needed unless we’ve scheduled a procedure. Bring a list of your medications, prior test results, and your insurance card. If fasting is needed, we’ll let you know in advance.

Will the doctor do any tests during my first visit? ▼

The first visit is usually a consultation to review your symptoms and medical history. If testing is needed, we’ll explain your options and schedule it for a future date.

GI conditions we treat at our Los Alamitos GI Clinic ▼

We address a wide range of gastrointestinal and liver issues, from GERD and IBS to IBD and liver disorders. We also offer colonoscopy and cancer screening services to support early detection and wellness.

We are accepting new patients for colon cancer screening ▼

Our Los Alamitos clinic welcomes new patients seeking colon cancer screening. Starting at age 45 or earlier if you're high risk, our colonoscopy services are coupled with prep guidance and follow-up.

What to expect during your first gastroenterology appointment ▼

During your initial visit, we will review your medical history, discuss your GI symptoms, and recommend appropriate diagnostics or treatment plans, such as endoscopies or labs.

What is a colonoscopy and how to prepare ▼

A colonoscopy checks for polyps and cancer in the colon. You’ll receive detailed prep instructions, follow a clear-liquid diet, and have the procedure with comfort-focused sedation.

Conditions We Treat at the Los Alamitos GI Clinic ▼

GERD (acid reflux)
IBS
Crohn’s disease & ulcerative colitis
Constipation & diarrhea
Colon polyps & colorectal cancer
Liver disease & hepatitis
Gallbladder & pancreatic disorders
Hemorrhoids & anal fissures

GI Services Offered at Our Los Alamitos Office ▼

Colonoscopy in Los Alamitos
Flexible Sigmoidoscopy
Upper Endoscopy (EGD)
Capsule Endoscopy
Liver function testing & Fibroscan
Hemorrhoid Banding Therapy
SIBO breath testing
ERCP & endoscopic ultrasound (EUS)
Nutrition counseling & dietary support

Getting Here: Directions to Our Los Alamitos GI Clinic ▼

Address:
Unio Specialty Care – Gastroenterology
4772 Katella Ave #200, Los Alamitos, CA 90720
Phone: (562) 596-5552

From Los Alamitos

Our office is located in central Los Alamitos on Katella Ave. Simply head toward Katella Ave and enter the medical plaza at #200.

From Cypress

Head south on Valley View St, turn left onto Katella Ave, and continue to the medical plaza at 4772 Katella Ave.

From Seal Beach

Take Seal Beach Blvd north, turn right onto Katella Ave, and our clinic will be on your left near Los Alamitos Blvd.

From Rossmoor

Travel north on Los Alamitos Blvd, turn right on Katella Ave, and our office will be on your left in the medical building.

From Hawaiian Gardens

Drive south on Norwalk Blvd, turn right onto Katella Ave, and continue until you reach our Los Alamitos location.

From Lakewood

Take Lakewood Blvd south, turn right onto Carson St, then left onto Bloomfield Ave. Continue to Katella Ave and turn right. Our office is just ahead.

From Garden Grove

Head south on Valley View St, turn left onto Katella Ave, and continue east until you arrive at our clinic.

From Stanton

Travel west on Katella Ave directly into Los Alamitos. Our clinic will be on your right side at 4772 Katella Ave.

From Westminster

Take Goldenwest St north to Katella Ave, turn left, and drive west into Los Alamitos. Our clinic is located near Los Alamitos Blvd.

From Buena Park

Head south on Valley View St, turn left onto Katella Ave, and drive east to our medical office building on the right.

Ready to Make an Appointment?

We are the largest gastroenterology physician group in California. Our organization is committed to providing high-quality, patient-centered care in a private practice setting. Our physicians are experts in the diagnosis and treatment of diseases of the gastrointestinal system, including those of the esophagus, stomach, colon, liver, small intestine, gallbladder, pancreas, and biliary tract.

Make an appointment today to start your journey to better health!