Table 2.

The individual studies’ definitions of diarrhea.

RCT	Definition of Diarrhea
Tankanow et al., 1990	One or more abnormally loose bowel movements/day throughout the study period of one to 10 days (parental reports)
Vanderhoof et al., 1999	The presence of at least two liquid stools/day during at least two observation periods during the course of the study
Arvola et al., 1999	At least three watery or loose stools/day for a minimum of two consecutive days
Erdeve et al., 2004	Three or more watery stools/day during antibiotic treatment
Duman et al., 2005	A change in bowel habits with at least three semi-solid or watery bowel movements/day for at least two consecutive days
Park et al., 2007	Not specified (self-report)
Cindoruk et al., 2007	Not specified (modified De Boer questionnaire categorizing diarrhea into “none”, “mild”, “moderate” and “severe”)
Conway et al., 2007	Three or more loose stools/day over at least two consecutive days during the 12-day follow-up period
Imase et al., 2008	“Loose or mostly loose stools”, not specified further
Kim et al., 2008	Not specified other than categorized in groups (“none”, “mild”, “moderate”, “severe”)
Merenstein et al., 2009	Not specified (parental reports)
De Vrese et al., 2011	Three or more watery stools for at least one day (where at least one episode lay within the eradication week)
Ojetti et al., 2013	Not specified other than categorized in groups (“none”, “mild”, “moderate”, “severe”)
Chatterjee et al., 2013	Passage of at least three or more watery or loose stools/day for at least two consecutive days
Zojaji et al., 2013	Not specified (self-report)
Fox et al., 2014	Categories:
	“A” (stool consistency ≥ 5, ≥2 stools/day for ≥2 days)
	“B” (stool consistency ≥ 5, ≥3 stools/day for ≥2 days)
	“C” (stool consistency ≥ 6, ≥2 stools/day for ≥2 days)
	“D” (stool consistency ≥ 6, ≥3 stools/day for ≥2 days)
Olek et al., 2017	≥3 loose/watery stools/24 h starting after the initiation of antibiotic treatment