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Dr. B. Mark Zhao is a colorectal surgeon who cares for patients with conditions of the colon, rectum and anus. His expertise encompasses inflammatory bowel diseases, such as Crohn's disease and ulcerative colitis; colon, rectal and anal cancers; diverticulitis (infection or inflammation of small pouches in the intestines); and pelvic floor disorders, including rectal prolapse, fecal incontinence (problems with bowel control) and constipation. He specializes in using minimally invasive surgical techniques to treat many of these conditions. He also performs colonoscopies and endoscopies to screen for or diagnose conditions of the colon and rectum.

Zhao conducts research on colorectal surgical outcomes, with the goal of making these procedures safer and more effective. He has a particular interest in using biomedical informatics (health-related datasets) to improve patient care.

Zhao earned his medical degree from the University of Iowa Carver College of Medicine. He completed a residency in general surgery at the University of California, San Diego, where he also earned a master of advanced study degree in clinical research and completed a fellowship in clinical informatics. He completed a fellowship in colon and rectal surgery at Washington University in St. Louis, training at Barnes-Jewish Hospital.

  • Board Certifications

    American Board of Colon and Rectal Surgery, Colon and Rectal Surgery, 2024

    American Board of Preventive Medicine/Toxicology, Clinical Informatics, 2024

    American Board of Surgery, Surgery, 2022

  • Fellowships

    Washington University School of Medicine, 2023

  • Residencies

    University of California San Diego-General Surgery, General Surgery, 2022

    University of California San Diego-General Surgery, General Surgery, 2017

  • Internship

    University of California San Diego-General Surgery, General Surgery, 2016

  • Education

    University of Iowa Roy J. and Lucille A. Carver College of Medicine, 2015

  • Languages

    English

As a colorectal surgeon, I am devoted to providing compassion, empathy and unwavering support to all my patients through challenging times.

My reviews

4.9

Overall Experience
91 Ratings
About our process
Mar 24, 2025
Dr. Zhao wrote down everything we needed to do for future care and what the next steps were. It would also be helpful if that same info was also in our summary visit within the MyChart app.
Mar 15, 2025
All good
Feb 08, 2025
Very nice Doctor
Feb 08, 2025
Caring & compassionate provider !
Feb 06, 2025
Stellar experience. Doctor treated me like an equal, was warm and friendly, and provided a good deal of information.
Feb 02, 2025
Dr Zhao gave found advice on a very complex medical problem.
Dec 15, 2024
Dr. Zhao was excellent to work with. He had obviously prepared thoroughly for my visit and inspired my complete confidence in his skills as a physician and surgeon.
Dec 06, 2024
Dr.Zhao & Diana Rago are true professionals. They treat you with respect and make you feel like you are important to them .
Aug 03, 2024
Dr.Zhao makes you feel comfortable and is very personable.
Jul 11, 2024
5 star experience during a difficult time makes a world of difference. It's so nice to have a doctor that shows emotion and empathy
Jun 18, 2024
Everything was excellent
Jun 16, 2024
Professional, knowledgeable, kind-highly recommend
Jun 05, 2024
Care provider was excellent.
Apr 27, 2024
Kind. Supportive. Clearly very knowledgeable
Apr 27, 2024
Excellent Dr Zhao and staff
Apr 20, 2024
Superb!
Mar 28, 2024
Mark Zhao was excellent. Caring, clear, and with a sense of humor, which given his area of practice, is useful.
Mar 09, 2024
Dr. Zhou is awesome!
Mar 08, 2024
All are very good

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