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Clin Asst Prof Calvin Ong Jianming

Clin Asst Prof Ong

MBBS (Singapore), MRCS(Edin), M.Med (Surg), FRCSEd (General Surgery)


Specialty: General Surgery

Conditions Treated by this Doctor:
Colorectal Cancer, Hernia, Inflammatory Bowel Disease.

Clinical Appointments

  • Consultant Surgery Changi General HospitalChangi General Hospital
  • Consultant Colorectal Surgery Changi General HospitalChangi General Hospital


Dr Ong is a consultant with the Department of Surgery at Changi General Hospital (CGH). He graduated from the National University of Singapore (NUS), School of medicine, in 2008 before completing his general surgical training in June 2016. Dr Ong obtained a fellowship from the Royal College of Surgeons of Edinburgh in 2016. His interests are in minimally invasive laparoscopic colorectal surgery for both benign and malignant conditions as well as inflammatory bowel disease.

Apart from the clinical work, he participates actively in educating the undergraduates from Yong Loo Lin School of Medicine and the Lee Kong Chien School of Medicine as well as postgraduate surgical trainees from the Singhealth Residency Programme. His exemplary and outstanding behaviour has won him the NUS role model educator award in 2014.


  • FRCSEd (Gen Surg)
  • MMed (Surg)
  • MRCS
  • MBBS (Singapore)

Professional Appointments and Committee Memberships

  • Clinical Assistant Professor - Duke-NUS
  • Clinical Lecturer - NUS Yong Loo Lin School of Medicine
  • Clinical Lecturer - NTU Lee Kong Chian School of Medicine
  • Fellow - Royal College of Surgeons Edinburgh
  • Physician Faculty Member - SingHealth General Surgery Residency Programme
  • Singapore Colorectal Society - Member


  • NUS role model educator award, 2014

Research Interests


• A minimally invasive surgical approach to synchronous anal and colon adenocarcinoma: review of existing literature. Tan JK, Teo NZ, Ong CJ, Yusof SB, Wijaya R. Int J Colorectal Dis. 2016 Aug;31(8):1543-5. doi: 10.1007/s00384-016-2572-z. Epub 2016 Mar 29.

Research Trials