Language English, Mandarin, Hokkien, Cantonese, Teochew
Associated Treatments
  • Robotic and laparoscopic colorectal surgery
  • Treatment of advanced colon and rectal cancer
  • Colonic stenting for obstructed colorectal cancer
  • Surgery for piles, anal fistulas and anal fissures
  • Surgery for inflammatory bowel disease (crohn’s disease and ulcerative colitis) and diverticular disease
  • Trans-anal endoscopic surgery for rectal tumours
  • Endoscopy and colonoscopy for cancer screening
  • Surgery for neuroendocrine and gastrointestinal stromal tumours(GIST)
  • Dr Tan Wah Siew is a general and colorectal surgeon at Mount Elizabeth Hospital, Singapore.
  • Her subspecialty interests are in minimally invasive colorectal surgery, proctology, colorectal cancer, advanced rectal cancer requiring pelvic lymph node dissections and pelvic exenterations and inflammatory bowel disease (IBD).
  • She spent a year training in Leeds, UK, gaining hands-on experience in robotic and laparoscopic colorectal surgery, complex pelvic surgeries and pelvic exenterations.
  • Prior to setting up her own private practice, Dr Tan was senior consultant surgeon at the Department of Colorectal Surgery, Singapore General Hospital (SGH), a tertiary referral centre with a high volume of complex colorectal cases.
  • She performed the first (in SGH) robotic lateral pelvic lymph node dissection for a patient with rectal cancer after neoadjuvant chemoradiation, as well as the first robotic pelvic exenteration for locally advanced rectal cancer in SGH. She has since gone on to perform numerous minimally invasive lateral pelvic lymph node dissections, using both laparoscopic and robotic techniques. To date, she has performed more than 500 major colorectal resection surgeries for both colorectal cancer and benign colorectal conditions.
  • She was also a member of the multi-disciplinary IBD Team at Singapore General Hospital. As one of the IBD surgeons in the team, she has performed many life-saving surgeries for patients with both ulcerative colitis and crohn’s disease.
  • In addition, she has a special interest in proctology, offering the range of surgical options for the treatment of haemorrhoids, anal fistulas and anal fissures.
  • She has conducted laparoscopic and endoscopic skills training courses for international and local delegates as well as surgical residents, and has also been involved in the teaching of nurses at Nanyang Polytechnic.
  • She has published widely in multiple peer-reviewed journals, particularly on minimally invasive colorectal surgery. She has been a reviewer for numerous local and international journals, including the Singapore Medical Journal, British Journal of Surgery, Colorectal Disease and International Journal of Colorectal Disease.
  • She has been a member of the Society of Colorectal Surgeons, Singapore (SCRS) since 2011, and was a member of its executive committee from 2014 to 2015. She is also a member of the Robotic Surgery Society of Singapore.

Key achievements

  • One of the earliest first Singaporean female surgeons to be trained in robotic colorectal surgery
  • Has performed numerous minimally invasive (both laparoscopic and robotic) lateral pelvic lymph node dissections for patients with advanced rectal cancer, as well as complete mesocolic excision surgery for colon cancer
  • Part of multi-disciplinary team that performed the first (in Singapore General Hospital) robotic pelvic exenteration for locally advanced rectal cancer



  • NUS Medical Society Excellence Award for Sports 1999
  • Singapore General Hospital Annual Scientific Meeting 2008 (Annual EBM Seminar): 1st prize for Best EBM (Surgery)
  • Singapore General Hospital Service Quality Award 2008
  • Singhealth Best Registrar Award 2008 and 2009
  • European Society of Coloproctology 5th Scientific and Annual General Meeting 2010: Lunchtime poster award (2nd prize)
  • Singapore General Hospital Annual Scientific Meeting 2011: Best Oral Paper (2nd prize)
  • Singapore Health Quality Service Award: Silver (2011)
  • Singapore Health Quality Service Award: Gold (2012)
  • 10 year Long Service Award, Singhealth (2014)
  • Service With a Heart Award, Singhealth (2017)
  • Singapore Health Quality Service Award: Silver (2020)


Fellowships and Accreditations
  • Bachelor of Medicine, Bachelor of Surgery, National University of Singapore
  • Master in Surgery, National University of Singapore
  • Fellow of the Academy of Medicine, Singapore
  • Fellow of the Royal College of Surgeons, Edinburgh
  • Specialist fellowship (robotic surgery, pelvic exenteration and surgery for inflammatory bowel disease) at St James University Hospital, Leeds, United Kingdom