Background
Rumination is characterized by the voluntary or involuntary regurgitation and rechewing of partially digested food that is either reswallowed or expelled. This regurgitation appears effortless, may be preceded by a belching sensation, and typically does not involve retching or nausea. In rumination, the regurgitant does not taste sour or bitter. [1]
Diagnostic criteria (DSM-5-TR)
The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) classifies rumination as a feeding and eating disorder. [2]
DSM-5 criteria for rumination are as follows:
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Repeated regurgitation of food over a period of at least 1 month. Regurgitated food may be re-chewed, re-swallowed or spit out.
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The repeated regurgitation is not attributable to an associated gastrointestinal or other medical condition (e.g., gastroesophageal reflux, pyloric stenosis).
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The eating disturbance does not occur exclusively during the course of anorexia nervosa, bulimia nervosa, binge-eating disorder or avoidant/restrictive food intake disorder.
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If the behavior occurs within the context of another mental disorder (i.e., generalized anxiety disorder) or neurodevelopmental disorder (i.e., intellectual disability), it must be sufficiently severe to warrant independent clinical attention.
Pathophysiology
While the pathophysiology of rumination remains unclear, a proposed mechanism suggests that gastric distention with food is followed by abdominal compression and relaxation of the lower esophageal sphincter; these actions allow stomach contents to be regurgitated and rechewed and then swallowed or expelled.
Several mechanisms for the relaxation of the lower esophageal sphincter have been proposed, including (1) learned voluntary relaxation, (2) simultaneous relaxation with increased intra-abdominal pressure, and (3) an adaptation of the belch reflex (eg, swallowing air produces gastric distention that activates a vagal reflex to relax the lower esophageal sphincter transiently during belching). Rumination may cause the following:
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Weight loss
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Growth failure
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Electrolyte imbalance
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Gastric disorders
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Upper respiratory tract distress
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Dental problems, particularly dental caries [3]
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Aspiration
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Choking
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Death
Epidemiology
Frequency
No systematic studies have reported the prevalence of rumination; most of the information about this disorder is derived from small case series or single case reports. Rumination disorder has been reported in children and adults with intellectual disability, as well as in infants, children, and adults of normal intelligence. Among those with otherwise normal intelligence and development, rumination is most common in infants. The prevalence of rumination in adults of normal intellectual functioning is unknown because of the secretive nature of the condition and because physicians lack awareness of rumination among this population.
Rumination is more common in individuals with severe and profound intellectual disability than in those with mild or moderate intellectual disability. Prevalence rates of 6%-10% have been reported among the institutionalized population of individuals with intellectual disability.
Demographics
Although rumination is rare in both males and females, it is reportedly more common among females. [4]
Rumination onset in otherwise normally developing infants typically occurs during the first year of life; onset usually manifests at age 3–6 months. [5] Rumination often remits spontaneously.
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In individuals with severe and profound intellectual disability, onset of rumination may occur at any age; the average age of onset is 6 years.
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Rumination among adolescents and adults of normal intelligence is gaining increased recognition.
Mortality/Morbidity
Rumination is estimated to be the primary cause of death in 5%–10% of individuals who ruminate. Mortality rates of 12%–50% have been reported in institutionalized infants and older individuals.
Prognosis
Little is known about the natural history and long-term outcome of individuals with rumination syndrome. The disorder remits spontaneously in infants more often than in older individuals. Rumination may persist for months to years.
