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David Armstrong, MA, MBChir

Ontario | Canada

Dr. David Armstrong is an Associate Professor of Medicine at McMaster University and an active consultant gastroenterologist at Hamilton Health Sciences. David Armstrong graduated from Cambridge University (1974) and King’s College Hospital (1977). After 2 years (1980-92) as a Family Physician in Goose Bay, Labrador he trained in internal medicine (UK: 1982-85), gastroenterology research (Guy’s Hospital, London, UK: 1985-88; University of Lausanne, Switzerland: 1988-92) and clinical gastroenterology (McMaster University: 1992-95).

David Armstrong has research interests in upper gastrointestinal disease, nutrition, education and practice audit; he is principal investigator for a number of multicentre studies on dyspepsia and gastroesophageal reflux disease with over 120 peer-reviewed publications, 70 invited articles and 200 peer-reviewed presentations at learned societies.

He was Chief of Clinical Service for Gastroenterology (2000-2007) and is Past-President of the HHS Medical Staff Association (2005-7), a member of the International Working Group on the Classification of Oesophagitis (IWGCO; 1994-present), a member of the Organizing Committee for the Annual CAG/CASL Canadian Gastroenterology Fellows’ Postgraduate Training Courses (1996-2007), Chair of the CAG Endoscopy Committee and a participant in the Canadian Consensus Conferences on the Management of Gastroesophageal Reflux Disease (1996 and 2004), Helicobacter pylori-related diseases (1998) and Upper Gastrointestinal Bleeding (2002), the Latin-American consensus on gastro-oesophageal reflux disease (2005) and the Montreal Definition and Classification of GERD Working Group.

As Chair of the CAG Endoscopy Committee, he has overseen the recent series of Canadian credentialing guidelines for gastrointestinal endoscopy; he was also a member of the Cancer Care Ontario Colonoscopy Standards Expert Panel (2007).

"SIBO Through the Eyes of Robert Koch and Austin Bradford Hill"

When first described, small intestinal bacterial overgrowth (SIBO) was considered to be a condition characterised by severe gastrointestinal (GI) dysmotility leading to malabsorption, usually in the context of structural or sensorimotor disorders of the GI tract such as bowel resection, adhesions, scleroderma or diverticulosis rendering the small intestine incapable of clearing resident bacteria which then caused disease by a variety of mechanisms. More recently, SIBO has been associated with a variety of conditions including iatrogenic hypochlorhydria, immune deficiency, post-surgical states, inflammatory bowel disease, liver disease, obesity, celiac disease, chronic pancreatitis, Parkinson's disease and other neurological conditions and, increasingly, the irritable bowel syndrome (IBS). Despite an increasing recognition of the importance of the GI microbiome in a number of clinical conditions, the syndrome of SIBO remains poorly understood due to limitations in defining the relevant microbial population, the symptomatology, the diagnostic tests, the underlying pathology and the most appropriate therapy. Research directed at improving the diagnosis and management of SIBO may benefit from considering Koch's postulates and Hill's criteria for causation to assess whether one or more specific bacteria are causally-related to the development of SIBO. 

Learning Objectives:

  • Appreciate the variety of mechanisms whereby bacterial overgrowth may occur in the small intestine.

  • Understand the limitations inherent in the diagnostic tests for SIBO.

  • Appreciate the treatment options for ameliorating the symptoms and signs of SIBO.

  • Appreciate the extent to which the current knowledge of SIBO fulfils Koch's postulates and Hill's criteria for causation.

  • Understand the potential opportunities for improving the diagnosis and treatment of microbiome-associated GI and systemic symptoms and signs attributed, currently, to SIBO.

Past Conference Participation 

2020 Integrative SIBO Conference - San Diego, California

~Featured Speaker~

"SIBO Through the Eyes of Robert Koch and Austin Bradford Hill"

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