Unio Specialty Care – Gastroenterology – Camarillo

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Unio Specialty Care – Gastroenterology – Camarillo

Office Hours

Monday

8:00 am - 5:00 pm

Tuesday

8:00 am - 5:00 pm

Wednesday

8:00 am - 5:00 pm

Thursday

8:00 am - 5:00 pm

Friday

8:00 am - 4:00 pm

Saturday

Closed

Sunday

Closed

Office Hours

Monday

8:00 am - 5:00 pm

Tuesday

8:00 am - 5:00 pm

Wednesday

8:00 am - 5:00 pm

Thursday

8:00 am - 5:00 pm

Friday

8:00 am - 4:00 pm

Saturday

Closed

Sunday

Closed

Shaham Mumtaz, MD

WELCOME!
Unio Specialty Care Gastroenterology – Camarillo welcomes Shaham Mumtaz to our practice

Kristine Corpuz, NP

WELCOME!
Unio Specialty Care Gastroenterology – Camarillo welcomes Kristine Corpuz to our practice

Karen Lathers, FNP-BC

WELCOME!
Unio Specialty Care Gastroenterology – Camarillo welcomes Karen Lathers to our practice

Nicole Engstrom, NP

Nicole is a board-certified Family Nurse Practitioner who cares for adults with a wide range of digestive disorders.

Dr. Ashwinee Condon is board-certified in gastroenterology and advanced endoscopy. She has extensive GI training at UCLA, first completing her general gastroenterology fellowship, and then staying on for an additional year for training in specialized GI procedures.

Jessica Fennewald, NP

Jessica completed her Bachelors of Science in Nursing at University of Missouri-Columbia in 2004. She started practicing at St. Luke’s Hospital in St. Louis, Missouri in the telemetry/Intensive Care Unit. Shortly after, she completed her Master’s degree at Maryville University in St. Louis, Missouri in 2010.

Jay Guan, MD

Dr. Jay Guan has extensive training in a broad range of GI disorders and procedures. His clinical focus includes Inflammatory Bowel Disease, Barret’s Esophagus, NASH, GI motility disorders, Hepatitis B/C, and Eosinophilic Esophagitis.

Karen Simon, MD

Dr. Karen Simon received her B.A. from Stanford University in 1996. She then attended Northwestern University for medical school.

Micha Rojany, MD

Dr. Micha Rojany was born and raised in Southern California. He received his undergraduate degree from the University of California, Berkeley. After, he attended USC Medical School and completed his internship and residency at Cedars-Sinai Medical Center in Los Angeles.

Justin Marasigan, DO

Dr. Justin Marasigan was raised in the Los Angeles area. He earned his undergraduate degree from the University of Southern California and his medical degree from Kirksville College of Osteopathic Medicine in Missouri.

Choose a Provider Below to Schedule an Appointment

If you are an existing patient, please select your provider

Justin Marasigan, DO

Micha Rojany, MD

Karen Simon, MD

Jay Guan, MD

Jessica Fennewald, NP

Ashwinee Condon, MD

Nicole Engstrom, NP

Karen Lathers, FNP-BC

Kristine Corpuz, NP

Shaham Mumtaz, MD

Reviews

Expert Gastroenterology Services in Camarillo – Accepting New Patients

At Unio Specialty Care – Gastroenterology in Camarillo, our board-certified GI specialists offer comprehensive digestive and liver health services in a patient‑centered setting. Conveniently located off Mission Oaks Blvd, our clinic is now welcoming new patients and accepts most major insurance plans.

Whether you’re preparing for a screening colonoscopy, managing chronic GI symptoms, or monitoring liver health, our skilled team provides advanced diagnostics and personalized treatment.

Our services include:

Colonoscopy & colorectal cancer screening
Upper endoscopy (EGD)
Flexible sigmoidoscopy & capsule endoscopy
ERCP & endoscopic ultrasound (EUS)
Liver evaluation & FibroScan testing
Hemorrhoid banding therapy
SIBO breath testing & nutrition counseling

Serving patients from:

Camarillo
Ventura
Oxnard
Somis
Point Magu
Newbury Park
Port Hueneme
Moorpark
Santa Rosa Valley
Thousand Oaks
Simi Valley
Fillmore
Santa Paula
Ojai
Castaic
Agoura Hills
and surrounding Ventura County communities.

GI conditions we treat at our Camarillo GI Clinic

Our Camarillo providers treat a wide variety of gastrointestinal and liver-related conditions, including GERD, IBS, IBD, liver disease, and gallbladder disorders. We also provide colonoscopy and colorectal cancer screening to support early detection.

We are accepting new patients for colon cancer screening

Our Camarillo clinic welcomes new patients seeking colon cancer screening. Recommended starting at age 45—or earlier for those with risk factors. Complete prep instructions and follow-up care are included.

What to expect during your first gastroenterology appointment

At your first visit, our doctors will review your health history, assess your symptoms, and discuss recommended diagnostic or treatment plans, including possible procedures such as an EGD or colonoscopy.

What is a colonoscopy and how to prepare

A colonoscopy allows our physicians to detect polyps or abnormalities in the colon. You’ll receive clear prep instructions, dietary guidance, and sedation options for maximum comfort. Learn more about colonoscopy screening.

Conditions We Treat at the Camarillo GI Clinic

Our comprehensive services include:

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

GI Services Offered at Our Camarillo Office

We offer a full suite of GI procedures including:

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

Frequently Asked Questions

Do I need a referral to see a gastroenterologist in Camarillo?

Some insurance plans require a referral, while others don’t. Our scheduling team will confirm this for you.

What conditions are treated at this location?

We treat GERD, IBS, IBD, liver disease, gallbladder issues, hemorrhoids, colon polyps, and more.

Is this clinic in-network with my insurance?

Yes—most major plans are accepted. We’ll verify your coverage and provide cost information before your visit.

When do I need to fast for my appointment?

No fasting is needed unless you have a scheduled procedure like colonoscopy or endoscopy.

Will tests be done during my first appointment?

First visits are usually consultative. We’ll schedule any necessary tests or imaging separately.

Do you offer colon cancer screening in Camarillo?

Yes—we offer colonoscopy and follow-up care beginning at age 45, or earlier if you’re at higher risk.

Highly Reviewed Gastroenterologist in Camarillo, CA

Doctors at InSite Digestive Healthcare, now Unio Specialty Care Gastroenterology, an affiliate of Unio Health Partners, in Camarillo have hospital or surgery center affiliations with:

Camarillo Endoscopy Center and Channel Islands Surgical Center
Camarillo Endoscopy Center
CMH Ventura Pleasant Valley
Camarillo St. Johns Regional Oxnard

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!