Table 1. A description of search strategies used in PubMed, Google Scholar, Science Direct, and Cochrane Library.

C. difficile: Clostridioides difficile, IBD: inflammatory bowel diseases

Database	Keywords	Search strategy	Filters	Search result
PubMed	C. difficile OR Clostridioides difficile OR Clostridium difficile AND inflammatory bowel disease	C. difficile OR Clostridioides difficile OR Clostridium difficile OR ("Clostridioides difficile/analysis"[Mesh] OR "Clostridioides difficile/classification"[Mesh] OR "Clostridioides difficile/drug effects"[Mesh] OR "Clostridioides difficile/etiology"[Mesh] OR "Clostridioides difficile/growth and development"[Mesh] OR "Clostridioides difficile/immunology"[Mesh] OR "Clostridioides difficile/microbiology"[Mesh] OR "Clostridioides difficile/pathogenicity"[Mesh] OR "Clostridioides difficile/physiology"[Mesh] ) AND inflammatory bowel disease OR IBD OR ( "inflammatory bowel diseases/analysis"[Mesh] OR "inflammatory bowel diseases/anatomy and histology"[Mesh] OR "inflammatory bowel diseases/complications"[Mesh] OR "inflammatory bowel diseases/diagnosis"[Mesh] OR "inflammatory bowel diseases/diet therapy"[Mesh] OR "inflammatory bowel diseases/drug therapy"[Mesh] OR "inflammatory bowel diseases/epidemiology"[Mesh] OR "inflammatory bowel diseases/etiology"[Mesh] OR "inflammatory bowel diseases/immunology"[Mesh] OR "inflammatory bowel diseases/microbiology"[Mesh] OR "inflammatory bowel diseases/physiopathology"[Mesh] OR "inflammatory bowel diseases/prevention and control"[Mesh] OR "inflammatory bowel diseases/therapy"[Mesh] OR "inflammatory bowel diseases/transmission"[Mesh])	Free full text, five years, humans, English, adult 19+ years, meta-analysis, randomized controlled trial, systematic review	346
Google Scholar	Inflammatory bowel disease and Clostridioides difficile and Clostridium difficile	Inflammatory bowel disease and Clostridioides difficile and Clostridium difficile	2017-2022	90
Science Direct	Inflammatory bowel disease and Clostridium difficile and Clostridioides difficile	Inflammatory bowel disease and Clostridium difficile and Clostridioides difficile	2017-2022, review article, research articles, case reports, open access only	115
Cochrane Library	Inflammatory bowel disease	Inflammatory bowel disease	2017-2022, infectious disease	2