John Marks, MD

John H Marks, MD, FACS, FASCRS is a colorectal surgeon, researcher, and educator who is internationally recognized for achieving unsurpassed colorectal cancer treatment outcomes and seeking the highest quality of life for patients with cancer and other colorectal conditions. The cornerstones of his approach are multimodal therapy, minimally invasive sphincter-preserving procedures, and, in select cases, no immediate surgery. He developed a laparoscopic method for performing a novel transanal-transabdominal proctectomy (TATA) procedure and then a transanal approach for performing a total mesorectal excision (taTME). By 2009, he reached the milestone of performing 1,000 laparoscopic colorectal operations. He was an early adopter of Transanal Endoscopic Microsurgery (TEM). As the first US site engaged in an ongoing Phase II Clinical Trial of the single port robot (Intuitive), he currently has the world’s largest experience with single-port robot abdominal and transanal colorectal operations. He also has the world’s largest experience working with Mini Robots in FDA-approved trials. Twenty years ago he piloted a Minimally Invasive Colorectal Surgery and Advanced Rectal Cancer Fellowship that is still one of only four such programs in the United States. Dr. Marks is especially honored to be a member of the Executive Committee of the American College of Surgeons National Accreditation Program for Rectal Cancer. As co-chair of the SAGES Oncology Taskforce, he champions the wider adoption of minimally invasive surgical approaches by surgeons who operate on cancers in other organ systems. His home base is Lankenau Medical Center in Wynnewood, PA. By far, he considers his biggest accomplishments to be those of his family: daughter Lizzie bachelor’s in Mathematics at Barnard College of Columbia University (2023), son Will Harvard Law School (2024), and daughter Victoria Yale School of Medicine (2026). He’s ever grateful to his wife Meredith—lawyer, mom, saint, and companion extraordinaire.