Portrait of B. Mark Zhao
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B. Mark Zhao, MD

Colon and Rectal Surgical Oncology
Colorectal Surgery Mission Bay
415-885-3606
Portrait of B. Mark Zhao
Portrait of B. Mark Zhao
ucsf logo

B. Mark Zhao, MD

Colon and Rectal Surgical Oncology
Colorectal Surgery Mission Bay
415-885-3606

On this page

About me

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, including transanal endoscopic microsurgery (a procedure using special instruments to remove rectal tumors without surgical incisions). 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.

Education & training

Board certification

  • Clinical Informatics, American Board of Preventive Medicine/Toxicology
  • Colon & Rectal Surgery, American Board of Colon and Rectal Surgery
  • General Surgery, American Board of Medical Specialties

Fellowship

  • Washington University School of Medicine

Residency

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

Degree

  • MD, University of Iowa College of Medicine

Academic title

  • Clinical Professor

My expertise

Locations

    Reviews

    Average rating

    4.8
    4.8 out of 5 Stars
    166 ratings
    About provider reviews

    Showing 1-6 of 42 reviews

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    • 5 out of 5 Stars
      May 29, 2026

      Excellent!

    • 5 out of 5 Stars
      May 28, 2026

      Professionals in communicating everything to me Thanks ...

    • 5 out of 5 Stars
      May 27, 2026

      Wonderful and positive experience, Dr Zhao is awesome

    • 5 out of 5 Stars
      May 6, 2026

      Just Excellent attention was given me I was visibly upset and they were kind. I'm just really worn out with my health problems and they were very kind to me

    • 5 out of 5 Stars
      April 22, 2026

      Dr. Zhao's team was quite impressive handling my care.

    • 5 out of 5 Stars
      March 25, 2026

      Dr. Zhao is just awesome!

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