Internal medicine

Cross-sectional study

Pathology

Odds ratio

Political science

Systematic review

MEDLINE

Functional constipation

Constipation

Population

Medicine

Meta-analysis

Environmental health

The Lancet. Gastroenterology & hepatology

<h2>Summary</h2><h3>Background</h3> Functional constipation is a common functional bowel disorder in the community, which has a varying prevalence across cross-sectional surveys. We did a contemporaneous systematic review and meta-analysis of studies using comparable methodology and all iterations of the Rome criteria to estimate the global prevalence of functional constipation. <h3>Methods</h3> In this systematic review and meta-analysis, we searched MEDLINE, Embase, and Embase Classic from Jan 1, 1990, to Dec 31, 2020, to identify population-based cross-sectional studies comprising at least 50 participants that reported the prevalence of functional constipation in adults (age 18 years and older) according to Rome I, II, III, or IV criteria. We excluded studies that reported the prevalence of functional constipation in convenience samples. We extracted prevalence estimates of functional constipation from eligible studies, according to the study criteria used to define it. For each study, we extracted data for country; method of data collection; criteria used to define functional constipation; whether the study used the Rome I, II, III, or IV diagnostic questionnaires or approximated these definitions of the condition using another questionnaire; the total number of participants providing complete data; age; the number of participants with the condition; the number of male and female participants; and the number of male and female participants with the condition. We calculated pooled prevalence, odds ratios (OR), and 95% CIs. <h3>Findings</h3> Of 8174 citations evaluated, 45 studies fulfilled the eligibility criteria, representing 80 separate populations and comprising 275 260 participants. The pooled prevalence of functional constipation was 15·3% (95% CI 8·1–24·4, <i>I</i><sup>2</sup>=99·4%) in studies using the Rome I criteria, 11·2% (7·9–14·9; <i>I</i><sup>2</sup>=99·6%) in studies that used Rome II criteria, 10·4% (6·5–14·9; <i>I</i><sup>2</sup>=99·8%) in those that used Rome III criteria, and 10·1% (8·7–11·6; <i>I</i><sup>2</sup>=98·2%) when Rome IV criteria were used. Prevalence of functional constipation was higher in women, irrespective of the Rome criteria used (OR 2·40 [95% CI 2·02–2·86] for Rome I, 1·94 [1·46–2·57] for Rome II, and 2·32 [1·85–2·92] for Rome III; no studies using Rome IV criteria reported prevalence by sex). There was significant heterogeneity between studies in all of our analyses, which persisted even when the same criteria were applied and similar methodologies used. <h3>Interpretation</h3> Even when uniform symptom-based criteria are used to define the presence of functional constipation, prevalence varies between countries. Thus, environmental, cultural, ethnic, dietary, or genetic factors can influence reporting of symptoms. Future studies should aim to elucidate reasons for this geographical variability. <h3>Funding</h3> None.

Global prevalence of functional constipation according to the Rome criteria: a systematic review and meta-analysis