Being that it is Colon Cancer awareness month, it is fitting that we are celebrating our 20 year anniversary of serving our community.

Gastrointestinal Medicine with Compassion and Care
SM Gastroenterology and SM Digestive Diagnostic Center are dedicated to providing our patients with exceptional quality care in the field of Gastroenterology. Our physicians and staff try to provide the highest standard of medical care in a safe, compassionate and professional environment. We are committed to taking the time to educate and provide treatment necessary to ensure your optimal digestive health.
Exceptional Care
Latest Equipment
24/7 Availability

Office Locations

Our group has three locations to conveniently serve patients on Central Coast and Santa Maria.

230 Station Way, Suite B Arroyo Grande, CA 93420

Phone: (805) 825-2727
Fax: (805) 614-6055

Monday – Friday: 8:00 AM – 5:00 PM
Saturday/Sunday: Closed

361 Town Center West, Suite 101 Santa Maria, CA 93458

Phone: (805) 922-6581
Fax: (805) 332-3900

Monday – Friday: 8:00 AM – 5:00 PM
Saturday/Sunday: Closed

Endoscopy Center 1315 South Miller St. Suite 101 Santa Maria, CA 93454

Phone: (805) 349-2945
Fax: (805) 349-2887

Monday – Friday: 8:00 AM – 5:00 PM
Saturday/Sunday: Closed

Our Procedures

Recent Google Reviews

Tonya Miller
There are many kind doctors but a doctor that is both kind and thorough is truly an unexpected experience. I'm thankful for the quality of care that his expertise offers. Plan to wait longer as a rule but know you are in an office of professionals that know what they are doing and keep in mind they will give you the same care when you are called.
I've been Dr. Hsia's patient for eight years. Our visits most always extend beyond routine service as this medical professional points me to nutritional and educational resources. I've learned so much from him! He is kind, courteous, thorough and I highly recommend him.
Paul Gutman
You will not find a more caring, compassionate, and smart doctor like Dr. Nastaskin!! He truly is the greatest doctor
Dwight Sorensen
Dr Nastaskin is a brilliant Gastroenterologist as well as kind and direct. His staff has always responded in a highly professional manner with great follow ups.
Karina Cerrato
Son muy hamables las chicas con uno y mi doctor es muy buen doctor Benphil su nombre nunca lo puedo recordar pero siempre me ayuda con el problema de mi Colón
Alexander Caballero
The wait for the appointment was a bit long but when I met him he was genuinely a caring doctor with a wonderful demeanor about him. If you want someone with a great attitude towards his patience then I recommend Dr. Hsia.
Sharon Wilcox
I had been suffering from diarrhea for over two years with no help from my local doctor. I went to Dr. Robert Evans and he was a doctor that was able to "think out of the box" of usual problems. It took him a short time to get my problem under control. So grateful for his help.
See All Google Reviews

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