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Dr Kewin Siah

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  • Senior Consultant, Division of Gastroenterology and Hepatology, Department of Medicine, National University Hospital
  • Assistant Professor, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore
  • Clinical lecturer, Department of Medicine, National University of Singapore


MBBS (London), MRCP (UK), FAMS (Gastroenterology)



Clinical Disciplines/Programmes:

Gastroenterology & Hepatology, Medicine

Special Interests:

Irritable Bowel Syndrome (IBS), Bloating, Constipation, Diarrhoea, Reflux

Find Out More:


Dr. Kewin Siah is a gastroenterologist specialised in Functional Gastrointestinal Diseases (FGID). He completed his specialist training at National University Hospital and underwent further colonoscopy training at Kyoto Prefectural University of Medicine in Japan, as part of the JSGE research fellowship award. He also received the NMRC award to perform to study Irritable Bowel Syndrome (IBS) in Oppenheimer Neurobiology of Stress Centre in UCLA. He is currently running the Gastro Motility Lab and a multi-disciplinary IBS Clinic in NUH.

Dr. Siah is an assistant professor of the Department of Medicine, Yong Loo Lin School of Medicine. He has been regularly speaking at various local and regional conferences on FGID, and has had multiple publications in international peer-reviewed journals. He is now the Secretary General of Asian Neurogastroenterology and Motility Association, President of Singapore’s IBS Support Group and Executive Committee of National Foundation Digestive Disease.

Journals & Publications

  1. Siah KT. Acid inhibitors and allergy: comorbidity, causation and confusion. Nat Commun. 2020;11(1):3950.
  2. Siah KT, Santosa A, Cheung CKY, Soh AYS, Bigliardi PL. Atopic Patients Who Fulfilled Rome III Criteria for Irritable Bowel Syndrome Had Higher Animal Danders Sensitization. J Neurogastroenterol Motil. 2020;26(2):267-273.
  3. Siah KT, Rahman MM, Ong AML, et al. The Practice of Gastrointestinal Motility Laboratory During COVID-19 Pandemic: Position Statements of the Asian Neurogastroenterology and Motility Association (ANMA-GML-COVID-19 Position Statements). J Neurogastroenterol Motil. 2020;26(3):299-310.
  4. Siah KT, Gong X, Yang XJ, Whitehead WE, Chen M, Hou X, Pratap N, Ghoshal UC, Syam AF, Abdullah M, Choi MG, Bak YT, Lu CL, Gonlachanvit S, Boon CS, Fang F, Cheong PK, Wu JCY, Gwee KA. Rome Foundation-Asian working team report: Asian functional gastrointestinal disorder symptom clusters. Gut. 2018 Jun;67(6):1071-1077. doi: 10.1136/gutjnl-2016-312852. Epub 2017 Jun 7. PubMed PMID: 28592440.
  5. Siah KT. Dyssynergic defecation: The not so hidden partner in constipation. (Editorial) Indian J Gastroenterol. 2018 May;37(3):186-188. doi: 10.1007/s12664-018-0866-5. Epub 2018 Jul 4. PubMed PMID: 29971688.
  6. Siah KT, Wong RK, Chan YH, Ho KY, Gwee KA. Prevalence of IBS in Singapore and its Association with Dietary, Lifestyle and Environmental Factors. J Neurogastroenterol Motil. 2016 Mar 8. doi: 10.5056/jnm15148. [Epub ahead of print] PubMed PMID: 26951047.
  7. Siah KT, Gwee KA. Rome IV Exploratory Model Closely Resemble Asian Functional Gastrointestinal Disorder Symptom Clusters. Clin Gastroenterol Hepatol. 2019 Apr;17(5):1002. doi: 10.1016/j.cgh.2018.09.027. PubMed PMID: 30902227.
  8. Siah KT, Wong RK, Whitehead WE. Chronic Constipation and Constipation-Predominant IBS: Separate and Distinct Disorders or a Spectrum of Disease? Gastroenterol Hepatol (N Y). 2016 Mar;12(3):171-8. PubMed PMID: 27231446; PubMed x
  9. Siah KT, Wong RKM, Ho KY. Melatonin for the Treatment of IBS. World J Gastroenterol. 2014 Mar 14;20(10):2492-2498. Review. PMID: 2462758
  10. Quek SXZ, Loo EXL, Demutska A, Chua CE, Kew GS, Wong S, Lau HX, Low EXS, Loh TL, Lung OS, Hung ECW, Rahman MM, Ghoshal UC, Wong SH, Cheung CKY, Syam AF, Tan N, Xiao Y, Liu JS, Lu F, Chen CL, Lee YY, Maralit RM, Kim YS, Oshima T, Miwa H, Pang J, Siah KTH. Impact of the coronavirus disease 2019 pandemic on irritable bowel syndrome. J Gastroenterol Hepatol. 2021 Feb 21. doi: 10.1111/jgh.15466. Epub ahead of print. PMID: 33615534.

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