ICD-116B85	RUMINATION-REGURGITATION DISORDER Rumination-regurgitation disorder
ICD-10F98.21	Rumination disorder of infancy and childhood
DSM-5-TRF98.21	Rumination Disorder

1. Definition and nosology

Rumination-Regurgitation Disorder (ICD-11: 6B85 Rumination-Regurgitation Disorder; DSM-5-TR: F98.21) — characterized by voluntary or semi-voluntary regurgitation of swallowed food followed by re-chewing, re-swallowing, or spitting out. Not fully explained by a medical condition (gastroesophageal reflux or other GI disease).

2. History

• Term ‘mericism’ in ancient times.
• DSM-IV — As an infant and childhood disorder.
• DSM-5 (2013) — diagnosis at all ages.

3. Epidemiology

• Prevalence: rare in infants and children; 6–10% in patients with intellectual disability; increasing recognition in adults (especially comorbid with eating disorders).
• Comorbidity: ID, ASD, anxiety, BN, BED.

4. Aetiology and pathogenesis

• Behavioral conditioning — ‘post-prandial belching’ followed by regurgitation as a learned behavior.
• Stress and anxiety.
• In ID/ASD, self-stimulation with food.

5. Clinical features

• Regurgitation minutes to hours after food intake.
• Eating disorder outcomes: weight loss, malnutrition, electrolyte imbalance, dental erosion, halitosis.
• Social consequences: shame, social isolation.

6. Diagnosis

6.1 Unified diagnostic criteria

A. Recurrent regurgitation of swallowed food — DSM-5-TR: ≥ 1 month; ICD-11: several times a week over at least several weeks; rechewing, swallowing, or spitting.

B. Regurgitation is not related to a medical condition (e.g., reflux, pyloric stenosis, pyloric duodenum obstruction).

C. Does not occur in the context of anorexia, bulimia, BED, ARFID.

D. If occurring in the context of another mental disorder (especially ID, ASD), significant severity requires separate assessment.

6.2 Source-specific clarifications

• DSM-5-TR / ICD-11 — criteria overlap; the duration and the age threshold differ: DSM-5-TR requires ≥ 1 month, ICD-11 requires several times a week over at least several weeks and a developmental age of ≥ 2 years.

6.3 Diagnostic algorithm

1. Clinical interview.
2. Medical assessment — exclusion of GERD, pyloric pathology, gastroparesis (upper endoscopy, motility study).
3. Manometry — confirmation of functional regurgitation.
4. Weight and nutritional status.
5. Comorbid eating disorder screening.

6.4 Differential diagnosis

7. Examination and assessment

• Endoscopy, manometry, pH-monitoring.
• Complete blood count, electrolytes.

8. Treatment

1. Diaphragmatic breathing — first-line behavioral intervention (Chitkara D.K. et al. Am J Gastroenterol 2006; effect 50–70%).
2. Habit reversal — learning alternative behavior.
3. Biofeedback.
4. Stress management and CBT.
5. In ID/ASD, functional behavior analysis and ABA.
6. Medical: GERD with proton pump inhibitor initial intervention.

Source-specific specifications

• Rome Foundation criteria (functional GI).
• NICE NG69 — general eating disorder principles.

Treatment methods

1. Diaphragmatic Breathing — Slow abdominal breathing for 5–10 minutes after eating — prevents regurgitation.
2. Habit Reversal Training (HRT — Habit Reversal Training) — Developing alternative behaviors.
3. Biofeedback — Abdominal muscle control.
4. FBA — functional behavior analysis (in ID/ASD) — Analysis of behavior trigger and maintainer.

9. Prognosis

• Significant improvement with diaphragmatic breathing and habit reversal.

10. Myths and misconceptions

Myth 1: “Rumination is a form of GERD”

Evidence: distinct disorder; manometry and clinical model differ.

Myth 2: “Only medical surgery (Nissen) solves it”

Evidence: Nissen fundoplication ineffective for functional rumination and contraindicated; behavioral intervention first-line.

Myth 3: “The patient behaves ‘volitionally’, requires discipline”

Evidence: It is a semi-voluntary behavior, based on conditioning; punishment is ineffective.

Myth 4: “Antiemetics are effective”

Evidence: Antiemetics (e.g., ondansetron) ineffective in rumination.

Myth 5: “Cannot be discontinued in a patient with ID/ASD”

Evidence: Behavioral interventions are effective; active intervention is essential for nutritional complications.

11. Sources

1. WHO. ICD-11. 6B85 Rumination-regurgitation disorder. 2024.
2. APA. DSM-5-TR. 2022.
3. Chitkara D.K., Van Tilburg M., Whitehead W.E., Talley N.J. Teaching diaphragmatic breathing for rumination syndrome. Am J Gastroenterol 2006;101(11):2449–2452.
4. Rome IV Diagnostic Criteria for Disorders of Gut-Brain Interaction. Rome Foundation; 2016.