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Clin Asst Prof Webber Chan Pak Wo

Clin Asst Prof Webber Chan Pak Wo

MBBS (HK), MRCP (UK), Specialty Certificate in Gastroenterology (MRCP)

Senior Consultant

Singapore General Hospital

Specialty: Gastroenterology & Hepatology

Sub-specialties: Inflammatory Bowel Disease (Ulcerative Colitis and Crohn's disease), Diagnostic and Therapeutic Endoscopy, Colon Cancer Screening, Advanced Endoscopic Imaging, Small Bowel Enteroscopy (Balloon Enteroscopy and Spiral Enteroscopy)

Conditions Treated by this Doctor:
Alcoholic Liver Disease, Autoimmune Hepatitis, Chronic Constipation, Chronic Diarrhoea, Cirrhosis, Colonic Polyps, Colorectal Cancer Screening, Crohn's Disease, Fatty Liver, Functional Dyspepsia, Gastro-oesophageal Reflux Disease (GERD), Hepatitis B, Hepatitis C, Inflammatory Bowel Disease, Irritable Bowel Syndrome (IBS), Liver Fibrosis, Non-alcoholic Fatty Liver Disease (NAFLD), Ulcerative Colitis, Viral Hepatitis.

Clinical Appointments

  • Senior Consultant Gastroenterology & Hepatology Singapore General HospitalSingapore General Hospital
  • Director & Senior Consultant Inflammatory Bowel Disease Centre Singapore General HospitalSingapore General Hospital

Academic Appointments

  • Clinical Assistant Professor, Duke-NUS Graduate Medical School
  • Clinical Lecturer, Yong Loo Lin School of Medicine
  • Clinical Teacher, Lee Kong Chian School of Medicine


Dr. Webber Chan is a Senior Consultant gastroenterologist and Director of the Inflammatory Bowel Disease (IBD) Services at Singapore General Hospital (SGH), and Clinical Assistant Professor at Duke-NUS Medical School, Singapore. He is experienced in managing multiple conditions including gastroesophageal reflux disease, dyspepsia, irritable bowel syndrome, colon cancer screening, as well as hepatitis and chronic liver disease. His subspecialty expertise is inflammatory bowel disease which includes ulcerative colitis and Crohn’s disease. He is well versed in various diagnostic and therapeutic endoscopies, such as gastroscopy, colonoscopy, capsule endoscopy as well as balloon enteroscopy and spiral enteroscopy for small bowel disorders. He is a key member and trainer of the small bowel endoscopy service as well as colorectal cancer screening service in SGH.

Dr. Chan graduated from the University of Hong Kong before he completed his general physician and advanced Gastroenterology training at Singapore General Hospital. He holds the Membership of the Royal Colleges of Physicians of the United Kingdom (MRCP (UK)) and the Specialty Certificate in Gastroenterology (MRCP). He completed his advanced fellowship training in inflammatory bowel disease at Concord Repatriation General Hospital, Sydney, where he learnt various aspects of management of IBD, dilation of Crohn’s disease stricture, and participated in research leading to numerous publications. He also assisted in setting up the fecal microbiota transplantation service in Concord Hospital. 

Dr. Chan has authored numerous publications in peer-reviewed, high impact factor international medical journals and book chapter and has served as reviewers for journals. In addition, he has been regularly invited as a faculty/speaker in medical conferences both locally and regionally. He is actively involved in research in inflammatory bowel disease, and is an investigator of a number of clinical drug trials. These reflect his clinical expertise in the Inflammatory Bowel Disease field.

Dr. Chan holds academic appointments in the National University of Singapore (NUS), Duke-NUS and Lee Kong Chian School of Medicine. He has a strong interest in medical education and was awarded the Outstanding Faculty Award by SingHealth Residency in 2016. His dedicated, holistic, patient-centered care won him several ‘Service with a Heart’ Awards from SGH.


  • ​Specialty Certificate in Gastroenterology (MRCP) 2014
  • Member of Royal College of Physician (MRCP (UK)) 2010
  • MBBS University of Hong Kong 2003 

Professional Appointments and Committee Memberships

  • Clinical Assistant Professor, Duke-NUS Medical School
  • Clinical Lecturer, Yong Loo Lin School of Medicine, National University of Singapore
  • Clinical Physician Faculty Member, SingHealth Gastroenterology Senior Residency Program
  • Director of SGH Inflammatory Bowel Disease (IBD) Service 
  • Main Clinical Coordinator for the 2014 Joint Final M.Med (Internal Medicine)/ MRCP(UK) PACES examination
  • Member of Singapore Gastroenterology Society


  • Service with a Heart Award, Singapore General Hospital, September 2018
  • ​SingHealth Health Manpower Development Plan (HMDP) Award
  • Outstanding Faculty award 2016, SingHealth residency
  • Singapore Health Quality Service Award, (Gold Award), SingHealth, August 2015
  • Service with a Heart Award, Singapore General Hospital, June 2015
  • Service Quality Award, Singapore General Hospital, February 2012

Research Interests



  1. High prevalence of Crohn's disease and ulcerative colitis in the elderly: a population-based study in Sydney, Australia
    Aviv Pudipeddi, Jeffrey Sung Ming Liu, Viraj Kariyawasam, Thomas J Borody, James Lawrence Cowlishaw, Charles McDonald, Peter Katelaris, Grace Chapman, Crispin Corte, Daniel A Lemberg, Cheng Hiang Lee, Anil Keshava, John Napoli, Robert Clancy, Webber Chan, Sudarshan Paramsothy, Rupert WL Leong

 Med J Aust 2020 (Accepted manuscript)

2.     Incidence of suboptimal response to tumor necrosis factor antagonist therapy in inflammatory bowel disease in newly industrialised countries: the EXPLORE study
Jesus K Yamamoto-Furusho , Othman Al Harbi , Alessandro Armuzzi , Webber Chan , Enrique Ponce de Leon , Jiaming Qian , Marina Shapina , Murat Toruner , Chia-Hung Tu , Byong Duk Ye , Morgane Guennec , Cecilia Sison , Dirk Demuth , Olga Fadeeva , Qasim M Rana Khan
Dig Liver Dis. 2020;52(8): 869-877. 

  1. Gastroenterologists' Preference and Risk Perception on the Use of Immunomodulators and Biological Therapies in Elderly patients with Ulcerative Colitis – an International Survey
     Webber Chan, Viraj C Kariyawasam, Shin Kim, Aviv V. Pudipeddi, Sudarshan Paramsothy, Hang Hock Shim, Fadi H. Mourad, Nik Ding, Marc Farrante, Rupert W. Leong
     Eur J Gastroenterol Hepatol. 2020; 32(8):976-983.
  1. An intronic FTO variant rs16952570 confers protection against thiopurine-induced myelotoxicities in multi-ethnic Asian IBD patients.
    Balram Chowbay, Sylvia Chen, Wei Zhi Tan, Natalia Sutiman, Cindy Lim, Sze Sing Lee, Dr Wai Fook Leong, Madeline Tjai, Chunyan Wang, San Choon Kong, Sai Wei Chuah, Brian Schwender, Pak Wo Chan, Hang Hock Shim, Wee Chian Lim, Chiea Chuen Khor, and Khoon Lin Ling
    Pharmacogenomics J. 2020;20(3):505-515.

  2. A Global Survey of Gastroenterologists' Travel Advice to Patients with Inflammatory Bowel Disease on Immunosuppressive Agents and Management of Those Visiting Tuberculosis Endemic Areas
    Webber Chan, Hang Hock Shim, Siew C. Ng, Asia–Pacific Crohn's and Colitis Epidemiologic Study (ACCESS) Study Group, Jeffrey Liu, Christian Inglis, Kay Greveson, Brandon Barathy, Craig Haifer, Rupert W. Leong
    Journal of Crohn's and Colitis 2018;12(11):1261-1269.

  3. A review of vedolizumab and ustekinumab for the treatment of inflammatory bowel diseases
    Shim HH, Chan PW, Chuah SW, Schwender BJ, Kong SC, Ling KL.
    JGH Open. 2018 ;2(5):223-234

  4. Entyvio Lengthen Dose Interval Study (ELDIS) - Lengthening vedolizumab dose interval and the risk of clinical relapse in inflammatory bowel disease
    Webber Chan , Nicole Lynch, Peter Bampton, Jeff Chang, Alvin Chung, Timothy Florin, David J. Hetzel, Simon Jakobovits, Gregory Moore, Paul Pavli, Graham Radford-Smith, Lena Thin, Brandon Baraty, Craig Haifer, Yunki Yau and Rupert W.L. Leong
    Eur J Gastroenterol Hepatol. 2018; 30(7): 735-740

  5. Crohn's disease associated strictures
    Webber Chan, Fadi Mourad, Rupert Leong
    J Gastroenterol Hepatol. 2018;33(5):998-1008
  1. Predictive role of NUDT15 variants on thiopurine-induced myelotoxicity in Asian inflammatory bowel disease patients.
    Sutiman N, Chen S, Ling KL, Chuah SW, Leong WF, Nadiger V, Tjai M, Choon Kong CS, Schwender BJ, Chan W, Shim HH, Lim WC, Khor CC, Cheung YB, Chowbay B.
    Pharmacogenomics. 2018;19(1):31-43.

  2. Review article: consensus statements on therapeutic drug monitoring of anti-tumour necrosis factor therapy in inflammatory bowel diseases
    Mitrev N, Vande Casteele N, Seow CH, Andrews JM, Connor SJ, Moore GT, Barclay M, Begun J, Bryant R, Chan W, Corte C, Ghaly S, Lemberg DA, Kariyawasam V, Lewindon P, Martin J, Mountifield R, Radford-Smith G, Slobodian P, Sparrow M, Toong C, van Langenberg D, Ward MG, Leong RW; IBD Sydney Organisation and the Australian Inflammatory Bowel Diseases Consensus Working Group.
    Aliment Pharmacol Ther. 2017;46:1037–1053

  3. Systematic review and meta-analysis: assessment of factors affecting disability in inflammatory bowel disease and the reliability of the inflammatory bowel disease disability index.
    Lo B, Prosberg MV, Gluud LL, Chan W, Leong RW, van der List E, van der Have M, Sarter H, Gower-Rousseau C, Peyrin-Biroulet L, Vind I, Burisch J.
    Aliment Pharmacol Ther. 2018; 47(1): 6-15
  1. Symptoms of anxiety and depression are independently associated with inflammatory bowel disease-related disability.
    Webber Chan, Hang Hock Shim, Miao Shan Lim, Fatimin Leila Bahjin Sawadjaan, Sangeetha Poongunam Isaac, Sai Wei Chuah, Rupert Leong, Chris Kong.
    Dig Liver Dis. 2017;49(12):1314-1319

  2. Inflammatory Bowel Disease Pharmacist Adherence Counseling Improves Medication Adherence in Crohn's Disease and Ulcerative Colitis
    Tiao DK, Chan W, Jeganathan J, Chan JT, Perry J, Selinger CP, Leong RW.
    Inflamm Bowel Dis. 2017;23(8):1257-1261

  3. Medication adherence in inflammatory bowel disease
    Webber Chan, Andy Chen, Darren Tiao, Christian Selinger, Rupert Leong.
    Intestinal Research 2017; 15(4): 434-445
  1. Colorectal cancer screening.
    Chan PW, Ngu JH, Poh Z, Soetikno R.
    Singapore Med J. 2017;58(1):24-28.

  2. Mycobacterium abscessus infection during ustekinumab treatment in Crohn's disease- a case report and review of literature
    Hang Hock Shim; Sophie Carrie Shan Cai; Webber Chan; Jenny Guek Hong Low; Hiok Hee Tan ;Khoon Lin Ling
    Journal of Crohn's and Colitis, jjy126 (Accepted manuscript)

  3. A patient with typhoid fever, Giardia lamblia gastroenteritis and hepatitis E.
    Qing Zhang,  Jonathan Guo Xiang Teh, and Webber Pak Wo Chan.
    Proceedings of Singapore Healthcare 2016, Vol. 25(1): 61– 63 

  4.  Ulcerative Colitis Diagnosed in a Patient after Primary Rectal Marginal Zone B-cell Lymphoma of Mucosa-Associated Lymphoid Tissue (MALT) Treated
    Webber Pak Wo Chan, Wei Qiang Leow.
    Proceedings of Singapore Healthcare 2015, Vol. 24(2): 123-129

  5. Chan, Webber Pak Wo. " Endoscopy in Inflammatory Bowel Disease: Asian Perspective—Singapore." Advances in Endoscopy in Inflammatory Bowel Disease. Ed. Hibi, Toshifumi, Hisamatsu, Tadakazu, Kobayashi, Taku. Japan: Springer, 2018. 261-265. Print. 
  1. Use of ustekinumab in Crohn's disease- Singapore largest single centre experience
    European Crohn's and Colitis Organisation Congress 2020
  2. Clinical Utility of Thiopurine Metabolite Monitoring in Inflammatory Bowel Disease and its Impact on Healthcare Utilization in Singapore
    Yeo JQ, Wee HL, Cheen HH, Wong SY, Lim TG, Leong WF, Chowbay B, Salazar E, Shim HH, Chan WPW, Kong SC, Ong WC
    European Crohn's and Colitis Organisation Congress 2020
  3. Barriers to prescribing anti-TNF therapy in inflammatory bowel disease (IBD) across newly industrialised emerging market countries: an analysis of the 'EXPLORE' study
    Byong Duk Ye; Jesus K Yamamoto Furusho; Qasim M Rana Khan; Olga Fadeeva; Dirk Demuth; Jiaming Qian; Igor L Khalif; Chia-Hung Tu; Murat Toruner;  Al Harbi Othman; Webber Chan; Enrique Ponce de Leon; Morgane Guennec; Cecilia Sison; Eleonora Uberti Foppa; Alessandro Armuzzi
    European Crohn's and Colitis Organisation Congress 2019 
  1. Phenotype and Natural History of Inflammatory Bowel Disease – Results from the Largest Center in Singapore
    Webber Chan , Miao Shan Lim , Andrew Tan , Kaina Chen, Aaron Gan, Teong Guan Lim, Wan Chee Ong , Brian John Schwender , San Choon Kong , Hang Hock Shim
    European Crohn's and Colitis Organisation Congress 2019

  2. Natural History of Inflammatory Bowel Disease from 1970 to 2017 – Results from a Large Single Center in Singapore
    Miao Shan Lim , Hang Hock Shim, Andrew Xia Huang, Tan, Kaina Chen, Aaron Tau Ming, Gan, Brian Schwender, Webber Pak Wo, Chan.
    Asia Pacific Digestive Week 2018 (Oral Poster Presentation)

  3. Vedolizumab Has Similar Incidence of Clostridium Difficile Infection In Comparison To Anti-TNF Therapies- A Retrospective Cohort Study
    Rangarajan Purushothaman, Aaron Tau-Ming Gan, Webber Pak Wo Chan, Cheng Yi Lee, Choon Jin Ooi, Sai Wei Chuah, Brian John Schwender, San Choon Kong, Wan Chee Ong, Teong Guan Lim, Hang Hock Shim.
    Asia Pacific Digestive Week 2018 (Poster Presentation)

  4. Incidence and Outcomes of Acute Severe Ulcerative Colitis (ASUC) – a retrospective cohort study in a Singapore Tertiary Institution
    Kaina Chen, Webber Chan, Choon Jin Ooi, Sai Wei Chuah, Brian John Schwender, Chris Kong, Wan Chee Ong, Teong Guan Lim, Hang Hock Shim.
    Asia Pacific Digestive Week 2018 (Oral Poster Presentation)

  5. A comparative study of infusion reactions associated with infliximab, vedolizumab and ustekinumab: Experience from a tertiary hospital in Singapore.
    Andrew Xia Huang, Tan, Hang Hock Shim, Wan Chee Ong , Teong Guan Lim, Webber Pak Wo Chan
    Asia Pacific Digestive Week 2018 (Oral Poster Presentation)

  6. Physician attitudes about the use of immunosuppressive therapy for inflammatory bowel disease in the elderly
    W.P.W. Chan, S. Kim, J.N. Ding, V. Kariyawasam, R.W. Leong
    European Crohn's and Colitis Organisation Congress 2018

  7. Physicians' recommendations for travel in patients with inflammatory bowel disease
    W.P.W. Chan, H.H. Shim, S.C. Ng, Asia–Pacific Crohn's and Colitis Epidemiologic Study (ACCESS) Study Group, J. Liu, C. Inglis, K. Greveson, R.W. Leong
    European Crohn's and Colitis Organisation Congress 2018

  8. Healthcare and medication utilisation in Singapore adult inflammatory bowel disease patients receiving immunomodulators and biologicsR.E.L. Gan, C.K.Y. Ng, W.C. Ong, W.P.W. Chan, B.J. Schwender, S.C. Kong, H.H. Shim ,K.L. Ling , S.W. Chuah , T.G. Lim
    European Crohn's and Colitis Organisation Congress 2018 

  9.  Severe small intestinal bleeding secondary to diffuse immune mediated enteritis after subtotal colectomy for steroid refractory ulcerative colitis

R. Purushothaman, S. Kong, P. Chan, S. Chuah, K. Lim, L. Choong, B. Tan, S. Mesenas, G. Tan, B. Schwender   United European Gastroenterology Week 2017

  1. Entyvio Lengthen Dose Interval Study (ELDIS): an audit of dose frequency versus remission
    Webber Chan; Glen Collins, David Hetzel, Simon Jakobovits, Graham Radford-Smith, Peter Bampton, Gregory Moore, Rupert W Leong

    Asia Pacific Digestive Week 2017 (Best of APDW 2017 - Plenary Abstracts Presentations)

  2. Comparison of infusion reactions to infliximab and vedolizumab – a retrospective analysis
    Webber Chan, Glen Collins , Esther Lee , Azeez Mahmoud , Rupert Leong
    Asia Pacific Digestive Week 2017 (Oral Presentation)

  3. The prevalence of inflammatory bowel disease in the City of Canada Bay, Sydney: A metropolitan population-based study
    JSM Liu, VC Kariyawasam, TJ Borody, P Katelaris, W Chan, J Cowlishaw,C Mcdonald, G Chapman, C Corte, W Selby, DA Lemberg, C Lee, A Keshava, J Napoli, R Clancy, RWL Leong
    Australia Gastroenterology Week 2017

  4. Vitamin D Deficiency in Asian IBD Patients: Prevalence and Effect of Vitamin D Supplementation on Disease Activity and Health-Related Quality-of-Life
    Ong, Wan Chee; Wan, Choon Nam; Ho, Choon Siang; Valerie Ng, Yun Ting; Lim, Teong Guan; Webber Chan, Pak-Wo; Kong, San Choon; Ling, Khoon Lin; Ong, Pei Shi
    Inflammatory Bowel Diseases: March 2016 (DOI: 10.1097/01.MIB.0000480178.73780.3b)

  5. Association of DHCR7/NADSYN1-rs12785878 and GC-rs7041 Polymorphism with Serum 25-Hydroxyvitamin D Levels in Singapore Chinese IBD Patients
    Ong, Wan Chee; Wan, Choon Nam; Valerie Ng, Yun Ting; Ho, Choon Siang; Lim, Teong Guan; Webber Chan, Pak-Wo; Kong, San Choon; Ling, Khoon Lin; Ong, Pei Shi
    Inflammatory Bowel Diseases: March 2016 (doi: 10.1097/01.MIB.0000480297.94219.b1)
  1. Relationship between psychological factors and inflammatory bowel disease-related disability in  Singapore
    Webber Pak Wo Chan, Hang Hock Shim , Sangeetha Poongunam Isaac , Sawadjaan Fatimin Leila Bahjin, Sai Wei Chuah, Chris San Choon Kong
    United European Gastroenterology Journal; 2015: 2 (Supplement 1)

Research Trials