Table 1.

Characteristics of the studies reviewed, arranged chronologically by year of publication.

Authors, Year	Region	Total Number of Subjects	Total Number of Cases	Study Population		Measure of Coffee Intake	Definition of Coffee Consumption (Lowest vs. Highest Category)	IBS Assessment Criteria
				Sexes Involved in Study	Age of Participants at Baseline (Years)
Khademolhosseini et al., 2011 [14]	Asia	1978	191	M + F	39	Baseline coffee intake, questionnaire	Consumer vs. abstainer	ROME II
Basandra et al., 2014 [15]	Asia	200	33	M + F	20.4	Baseline coffee intake, questionnaire	0 cups/day vs. >2 cups/day	ROME III
Guo et al., 2015 [16]	Asia	157	78	M + F	46.8/43.3	Baseline coffee intake, questionnaire	Consumer vs. abstainer	ROME III
Al Saadi et al., 2016 [28]	Asia	302	50	M + F	21.6	Baseline coffee intake, questionnaire	1 cup/day vs. >3 cups/day	ROME III
Kesuma et al., 2021 [29]	Asia	454	137	M + F	15.8	Baseline coffee intake, questionnaire	Consumer vs. abstainer	ROME III
Koochakpoor et al., 2021 [30]	Asia	3362	NR	M + F	36.1	Baseline coffee intake, questionnaire	Non-drinker vs. >3 cups/day	ROME III
El Sharawy et al., 2022 [31]	Africa	182	50	M + F	23.9	Baseline caffeine intake, questionnaire	Consumer vs. abstainer	ROME III
Wu et al., 2023 [32]	UK	425,387	7736	M + F	56.22	Baseline coffee intake, questionnaire	0.5–1 cups/day vs. 2–3 cups/day vs. ≥4 cups/day	ICD-10

NR = not reported.