Epidemiology of functional gastrointestinal disorders in children and adolescents: A systematic review

Table 1 Classification of functional gastrointestinal disorders in children and adolescents

	Rome IV nomenclature1	Frequency	Duration	Synonym, subtypes or approximate terms
H1: Functional nausea and vomiting disorders
H1a.	Cyclic vomiting syndrome	≥ 2 periods of intense, unremitting nausea and paroxysmal vomiting	h-d/6 mo	Periodic vomiting
H1b1.	Functional nausea	≥ 2 nausea episodes/wk	≥ 2 mo	Bothersome nausea
H1b2.	Functional vomiting	≥ 1 vomiting episode/wk	≥ 2 mo	-
H1c.	Rumination syndrome	Repetitive regurgitation and rechewing or expulsion of food	≥ 2 mo	Adolescent rumination syndrome2; regurgitation, reswallowing, spitting
H1d.	Aerophagia	Repetitive belching and/or increased flatus	≥ 2 mo	-
H2: Functional abdominal pain disorders
H2a.	Functional dyspepsia	≥ 1 symptom for ≥ 4 d/mo	≥ 2 mo	Postprandial distress syndrome;
				Epigastric pain syndrome
H2b.	Irritable bowel syndrome	Abdominal pain for ≥ 4 d/mo	≥ 2 mo	Abdominal discomfort2;
				Manning criteria
H2c.	Abdominal migraine	≥ 2 intense abdominal pain episodes	≥ 1 h/6 mo	Periumbilical pain2
H2d.	Functional abdominal pain - not otherwise specified	≥ 4 episodic or continuous abdominal pain/mo	≥ 2 mo	Functional abdominal pain2;
				Functional abdominal pain syndrome2
H3: Functional defecations disorders
H3a.	Functional constipation	≤ 2 defecations/wk	≥ 1 mo	-
		≥ 1 fecal incontinence/wk
H3b.	Nonretentive fecal incontinence	Episodes of fecal loss	≥ 1 mo	-

¹After appropriate evaluation, the symptoms cannot be fully explained by another medical condition;

²Rome III nomenclature.