About Us

Our Mission

Focused on Patient-Centered Endoscopic Care

At Zazen Surgery Center, our mission is to focus on medical care centered around same-day diagnostic endoscopic procedures for preventive, diagnostic, and therapeutic interventions for patients experiencing acute upper and lower gastrointestinal problems.

We have a strong customer-oriented team with years of experience in the field of gastroenterology and are convenient for patients looking for safe alternatives to surgical procedures outside of the hospital setting.

Quality & Safety

Zazen Surgery Center is one of the few AAAHC-accredited facilities in the region. We have a strong track record of quality-based care centered around current research-based safety standards and national quality metrics.

Board Certified Physician

Dr. Vivian Asamoah

Founder, Zazen Surgery Center & Houston Gastro Institute

Dr. Vivian Asamoah is a board-certified gastroenterologist and the founder of Zazen Surgery Center and its partner practice, Houston Gastro Institute. She trained at Johns Hopkins, completing her internal medicine residency at Johns Hopkins Bayview Medical Center and her fellowship in gastroenterology, hepatology and nutrition at The Johns Hopkins Hospital.

I strongly believe that the needs of the patient come first

Dr. Asamoah founded Zazen Surgery Center to give patients in Katy and the greater Houston area a calmer, more personal alternative to hospital-based endoscopy, without compromising on safety. Her focus is on careful, evidence-based care: thorough screening and diagnostic procedures, clear communication before and after every visit, and a center where patients feel informed and at ease from check-in to recovery.

Beyond the procedure room, Dr. Asamoah brings an integrative perspective to digestive health. Combining conventional gastroenterology with training in functional medicine, she looks at the genetic, biochemical and lifestyle factors behind each patient’s symptoms to build care plans that support lasting results. She and her multilingual team care for a diverse community of patients and take pride in making every patient feel heard.

Board Certified Physician

Dr. Ting-Hui Hsieh, MD

Dr. Hsieh is originally from Taiwan, where he attended the National Taiwan University College of Medicine. He completed the internal medicine residency and gastroenterology fellowship at the world-renowned National Taiwan University Hospital. He moved to the United States in 2006 and continued his training at the prestigious Mayo Clinic in Arizona for transplant hepatology and gastroenterology.

Dr. Hsieh is a member of the American Gastroenterological Association (AGA), American Society for Gastrointestinal Endoscopy (ASGE), American College of Gastroenterology (ACG), the American Association for the Study of Liver Diseases (AASLD), and the Gastroenterological Society of Taiwan. He is a manuscript reviewer of ACG Case Reports Journal and BMJ Case Reports. Dr. Hsieh has received several grants and awards, including USJMSCP-NIH-APASL Joint Symposium Young Investigator Award and the Mayo Clinic Bronze Quality Fellow. He is board certified in gastroenterology both in the USA and in Taiwan.

Dr. Hsieh is an established and highly skilled physician with over twenty years of experience in gastroenterology, hepatology and various endoscopic procedures, with more than 20,000 procedures performed over his career. With several providers and office staff fluent in Mandarin and Taiwanese, Dr. Hsieh and his practice are well in tune with the local Asian community. Dr. Hsieh has a clinical interest in liver disease including viral hepatitis B and C, metabolic dysfunction-associated steatotic liver disease (MASLD), liver cirrhosis, and pre- and post-liver transplant care. Additionally, he enjoys the practice of diagnosing and treating Helicobacter pylori infection, gastroesophageal reflux disease (GERD), Barrett’s esophagus, irritable bowel syndrome (IBS), constipation, hemorrhoids, defecation issues, inflammatory bowel disease (IBD), and colon cancer screening and prevention.

Dr. Hsieh’s passion is driven by the bonds he builds with his patients over the course of their lives and the enjoyment he holds in keeping them healthy and well. “I trust that you have honestly shared your history with me, from your daily digestive symptoms to the most personal concerns, to allow me to create the best possible treatment plan. My goal is to provide you with the greatest opportunity for health and healing.”

In his spare time, he enjoys spending time with his two sons, weight training, travel, photography, Jazz, fine art, motorcycle, tennis, swimming, and scuba diving. He is a PADI-certified rescue scuba diver.

The Name Behind the Center

What is Zazen?

Zazen is a meditative practice that helps achieve calm and insight into life and the nature of being. It's the spirit we bring to every patient interaction.

Customer-Oriented

A strong customer-oriented team with years of experience in gastroenterology. Convenient for patients looking for safe alternatives to surgical procedures outside the hospital setting.

AAAHC-Accredited

One of the few AAAHC-accredited facilities in the region. Quality-based care centered around current research-based safety standards and national quality metrics.

Independently Owned

As an independent surgery center, we offer a streamlined, hassle-free experience. Say goodbye to bureaucratic delays and focus on what truly matters — your health.

Patient Comfort

Upon request, we can provide an all-female staff for your procedure, catering to personal preferences and ensuring a comfortable experience for every patient.

I don't have enough time and/or space to talk about why this place is amazing. I just had my very first colonoscopy done here and I was a bit nervous. They put me right at ease. From the nurses to the anesthesiologist to the doctor himself I could not have been more comfortable. The whole experience was quick, smooth, and easy. Highly recommend!

Dr. Asamoah and team made my EGD procedure very comforting and wonderful. From start to finish her team made me feel safe and that I was in great hands. They're all so kind, heartwarming and professional. Last thing I remember before knocking out was Dr. Asamoah's infectious smile and kind words that put me at ease. I found my forever GI! I highly recommend this place.

My procedure (colonoscopy) went smoothly. The staff was professional. I was in and out in less than 2 hours. I arrived at 9am, waited in the lobby to be called to the back, then was prepped and I was out by 11 in my car. I would definitely recommend Dr. Vivian Asamoah and Zazen Surgery Center.

I recently underwent a colonoscopy/endoscopy procedure at Zazen Surgery Center. Throughout the entire process, the staff consistently checked in to ensure I was comfortable. I arrived at 7 am, and by 9:30 am, I was already on my way home. The combination of a friendly and professional staff, focus on patient comfort, and impressive efficiency made the entire process not only smooth but surprisingly bearable.

Great experience and would highly recommend Zazen Surgery Center to all my family and friends. The front desk and procedure room staff are all attentive and caring and made me feel at ease. I was in and out of there in no time. It was such a good feeling when Dr. Obuaya, my anesthesiologist, talked to me first before the procedure. Two thumbs up for the doctors and staff.

Fast and efficient. Friendly staff - very competent. Got a very nice 'follow-up' call the next day to ensure I was feeling alright - very nice. And a nice, clean surgery center.

The staff is great. They listened to my questions and provided good answers. The facility is clean and well-maintained.

Clean, modern, and efficient. All the staff from reception to the nurses were competent and professional. I'd like to say I'd return again without hesitation - but I'd rather not have another colonoscopy.

I will highly recommend Zazen as the place to go to!! From the front desk to everyone I encountered were super nice, welcoming and made you feel beyond comfortable. Thank you so much to everyone at Zazen. You guys were beyond amazing!! THANK YOU!!!

This is my second colonoscopy. 1st time here, absolutely no complaints. Staff very friendly and helpful, very professional. I will strongly refer friends and family, definitely come back if needed. Thank you!

Fast and efficient. Friendly staff - very competent. Got a very nice 'follow-up' call the next day to ensure I was feeling alright - very nice. And a nice, clean surgery center.

The staff is great. They listened to my questions and provided good answers. The facility is clean and well-maintained.

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Take the first step toward proactive health care. Our team handles insurance verification and accepts most insurance plans, with competitive cash-pay options for the uninsured. No referral needed for most insurance plans.

Schedule Procedure (281) 869-3011

About Us

Focused on Patient-Centered Endoscopic Care

Quality & Safety

Meet Our Doctors

Dr. Vivian Asamoah

Dr. Ting-Hui Hsieh, MD

What is Zazen?

Customer-Oriented

AAAHC-Accredited

Independently Owned

Patient Comfort

What Our Patients Say

Ready to Schedule Your Procedure?

Serving the Greater Houston Metro & Surrounding Areas

Katy & West Houston

Houston Metro