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John H Marks, MD

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Practice Philosophy

At Marks Colorectal Surgical Associates, we practice tomorrow’s medicine today, and are committed to a multidisciplinary, compassionate, and collaborative mode of care that puts our patients first. We are advancing colorectal surgery and care in ways that have, and will continue to, lead standards of care for colorectal cancer treatment on an international level, and our surgeons are pioneers in laparoscopic and robot-assisted colorectal procedures which reduce pain, blood loss and recovery time, as well as help patients preserve normal function and avoid colostomy bags.

Practice Name
Marks Colorectal Surgical Associates
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This doctor is employed by Main Line HealthCare, the multispecialty physician network of Main Line Health, including more than 350 community and hospital-based physicians.

Locations and Appointments

Lankenau Medical Science Bldg, Suite 375
100 East Lancaster Avenue
Wynnewood, PA 19096
  • Phone: 610.645.9093
  • Fax: 610.645.9476
  • Accessibility: Public Transportation

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Call 1.866.CALL.MLH (1.866.225.5654), Monday through Friday between 8:00 am–6:00 pm ET, to speak with a member of our referral staff who can help find the doctor who is right for you.

About John H Marks, MD

John H Marks, MD, FACS, FASCRS, is director of the Colorectal Center at Lankenau Medical Center and chief of the section of colorectal surgery at Main Line Health. He is professor of surgery at the Lankenau Institute for Medical Research in Wynnewood, Pennsylvania. Dr. Marks directs a colorectal surgical research team and a fellowship in advanced rectal cancer management, one of only four in the United States.

Dr. Marks is a graduate of Yale University and the Jefferson Medical College of the Thomas Jefferson University where he received residency training in general surgery and colorectal surgery. He completed a fellowship in advanced laparoscopic colorectal surgery at the University of Nice, France under famed professor Jean Mouliel. Dr. Marks is board certified in general surgery and in colorectal surgery.

Dr. Marks' research and educational programs focus largely on minimally invasive laparoscopic colorectal surgery including and featuring radical sphincter preservation resection for rectal cancer after neoadjuvant therapy. He champions full thickness local excision (FTLE) by the transanal endoscopic microsurgical (TEM) method following neoadjuvant therapy for rectal cancer. The minimally invasive sphincter preserving rectal cancer patient series is one of the largest of its kind nationally and in the world. Dr. Marks and his team are dedicated to promoting enhancement of the quality of life for the colorectal surgical patient, and, in that context, there is a dominant educational effort. In a recent 12 month period, Dr. Marks, along with his colorectal surgical team, gave 62 scientific presentations, live televised surgical demonstrations, and instructional videos worldwide. In 2009, a landmark was reached with his performance of the 1,000th laparoscopic colon resection. Dr. Marks is widely published.

Dr. Marks currently serves as president of the Marks Colorectal Surgical Foundation, president of the Northeastern Society of Colon & Rectal Surgeons, and president of the International Society of Laparoscopic Colorectal Surgeons. He is the co-director of the Multidisciplinary International Rectal Cancer Group and the annual International Rectal Cancer Consensus Conference held at Lankenau Medical Center. He serves on and/or directs numerous committees in the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) and the American Society of Colon and Rectal Surgeons (ASCRS). He is on the editorial board of Surgical Endoscopy.

Dr. Marks, his wife, Meredith, and children, Victoria, William and Elizabeth, reside in Gladwyne, Pennsylvania.

  • Years of Experience: 22
  • Language: English
Specialties Accepting New Patients
Colorectal Surgery Board certified since 1997
General Surgery Board certified since 2004
Primary Affiliation
Academic Titles
  • Assistant Clinical Professor of Surgery
  • MCP/Hahnemann University School of Medicine
Clinical Titles
  • Chief, Colorectal Surgery


Medical school
  • Jefferson Medical College
  • Thomas Jefferson University Hospital
  • Thomas Jefferson University Hospital
  • Thomas Jefferson University Hospital

*Members of the Main Line Health medical staff are affiliated with Bryn Mawr Hospital, Lankenau Medical Center, Paoli Hospital and Riddle Hospital. Membership on the medical staff of any of our hospitals does not constitute an employment or agency relationship.

Awards & Memberships

Current Membership & Activities
  • American College of Surgeons
  • American Medical Association
  • Fellow, American Society of Colon and Rectal Surgeons
  • Association for Academic Surgery
  • American College of Physicians
  • Pennsylvania Medical Society
  • Northeastern Society of Colorectal Surgeons
  • Pennsylvania Society of Colon and Rectal Surgeons
  • Philadelphia County Medical Society
  • Society of American Gastrointestinal Endoscopic Surgeons
  • Society of Laparoendoscopic Surgeons
  • Society for Surgery of the Alimentary Tract

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