BackgroundRumination is characterized by the repeated regurgitation of food. Rumination syndrome is a disorder of gut‐brain interaction diagnosed by Rome criteria, whereas rumination disorder is a feeding and eating disorder diagnosed by DSM‐5 criteria. We aimed to determine the global prevalence of rumination according to these criteria across all age groups.MethodsWe performed a systematic review and meta‐analysis of studies reporting the prevalence of rumination syndrome according to Rome III and Rome IV and rumination disorder according to the following validated DSM‐5 assessments: PARDI, EDA‐5, EDY‐Q, STEP, and STEP‐CHILD. We searched MEDLINE, EMBASE, and PsychINFO (from January 1, 2006, to June 1, 2023) to identify studies reporting the prevalence of rumination in community settings in participants of any age. We did a meta‐analysis to estimate the pooled prevalence and odds ratio (OR) of rumination according to diagnostic criteria, country, and characteristics such as age and sex.Key ResultsThe search strategy generated 1243 studies, of which 147 studies appeared to be relevant. Thirty studies were included, with a total of 114,228 participants, of whom 61,534 of these were adults and 52,694 were children. The pooled prevalence of rumination syndrome in children of all ages according to Rome III criteria was 1.0% (95% CI 0.3–1.6; I2 91.1%), but no data were available for adults. According to Rome IV criteria, the pooled prevalence of rumination syndrome in children of all ages was 0.4% (95% CI 0.2–0.6; I2 56.4%) and 3.7% in adults (95% CI 2.3–5.1; I2 91.4%). The pooled prevalence of rumination disorder in children of all ages according to EDY‐Q was 2.1% (95% CI 0.9–3.4; I2 = 78.1%), but only one study utilizing EDY‐Q in adults was included (0.7% [95% CI 0.4–1.0]). No data were available for children or adults using any other validated DSM‐5 assessments for rumination disorder. Irrespective of diagnostic criteria, the pooled prevalence of rumination was higher in adults compared to children and adolescents (3.0% [95% CI 1.4–4.7; I2 = 98.1%] vs. 0.8% [95% CI 0.4–1.3; I2 = 90.8%]), but higher in adolescents than in children (1.1% [95% CI 0.3–2.0; I2 = 92.8%] vs. 0.1% [95% CI 0.0–0.2; I2 = 24.5%]). In adults, factors independently associated with rumination were female gender (OR 1.4 [95% CI 1.0–2.0]), anxiety (OR 2.3 [95% CI 2.1–2.6]), and depression (OR 1.8 [95% CI 1.2–2.9]). No association between gender and rumination was seen in children.Conclusions and InferencesThe prevalence of rumination is more common in adults than in children. In adults, rumination is associated with female gender, anxiety, and depression. Future population studies should aim to better understand why this behavior is more common in adults and also compare validated DSM‐5 assessments for rumination disorder with Rome criteria for rumination syndrome as prevalence may differ.