Terms such as functional colonic disease (or functional bowel<unk>  refer in medicine to a group of bowel<unk> s which are characterised by chronic abdominal complaints without a structural or biochemical cause that could explain symptoms. Other functional<unk> s relate to other aspects of the process of digestion. The consensus review process of meetings and publications organised by the Rome Foundation, known as the Rome process, has helped to define the<unk> s. Successively, the Rome I, Rome II, Rome III and Rome IV proposed consensual classification system and terminology, as recommended by the Rome Coordinating Committee. These now include classifications appropriate for adults, children and neonates/toddlers. The current Rome IV classification, published in 2016, is as follows: A. Esophageal<unk> s * A1. Functional chest pain * A2. Functional heartburn * A3. Reflux hypersensitivity * A4. Globus * A5. Functional dysphagia B. Gastroduodenal<unk> s * B1. Functional dyspepsia * B1a. Postprandial distress syndrome (PDS) * B1b. Epigastric pain syndrome (EPS) * B2. Belching<unk> s * B2a. Excessive supragastric belching * B2b. Excessive gastric belching * B3. Nausea and vomiting<unk> s * B3a. Chronic nausea vomiting syndrome (CNVS) * B3b. Cyclic vomiting syndrome (CVS) * B3c. Cannabinoid hyperemesis syndrome (CHS) * B4. Rumination syndrome C. Bowel<unk> s * C1. Irritable bowel syndrome (IBS) * IBS with predominant constipation (IBS-C) * IBS with predominant diarrhea (IBS-D) * IBS with mixed bowel habits (IBS-M) * IBS unclassified (IBS-U) * C2. Functional constipation * C3. Functional diarrhea * C4. Functional abdominal bloating/distension * C5. Unspecified functional bowel<unk>  * C6. Opioid-induced constipation D. Centrally mediated<unk> s of<unk>  pain * D1. Centrally mediated abdominal pain syndrome (CAPS) * D2. Narcotic bowel syndrome (NBS)/ Opioid-induced GI hyperalgesia E. Gallbladder and sphincter of Oddi<unk> s * E1. Biliary pain * E1a. Functional gallbladder<unk>  * E1b. Functional biliary sphincter of Oddi<unk>  * E2. Functional pancreatic sphincter of Oddi<unk>  F. Anorectal<unk> s * F1. Fecal incontinence * F2. Functional anorectal pain * F2a. Levator ani syndrome * F2b. Unspecified functional anorectal pain * F2c. Proctalgia fugax * F3. Functional defecation<unk> s * F3a. Inadequate defecatory propulsion * F3b. Dyssynergic defecation G. Childhood functional GI<unk> s: Neonate/Toddler * G1. Infant regurgitation * G2. Rumination syndrome * G3. Cyclic vomiting syndrome (CVS) * G4. Infant colic * G5. Functional diarrhea * G6. Infant dyschezia * G7. Functional constipation H. Childhood functional GI<unk> s: Child/Adolescent * H1. Functional nausea and vomiting<unk> s * H1a. Cyclic vomiting syndrome (CVS) * H1b. Functional nausea and functional vomiting * H1b1. Functional nausea * H1b2. Functional vomiting * H1c. Rumination syndrome * H1d. Aerophagia * H2. Functional abdominal pain<unk> s * H2a. Functional dyspepsia * H2a1. Postprandial distress syndrome * H2a2. Epigastric pain syndrome * H2b. Irritable bowel syndrome (IBS) * H2c. Abdominal migraine * H2d. Functional abdominal pain ‒ NOS * H3. Functional defecation<unk> s * H3a. Functional constipation * H3b. Nonretentive fecal incontinence
Functional gastrointestinal disorder
Functional constipation
Neurogenic bowel dysfunction
Purging disorder
Irritable bowel syndrome
Obstructed defecation
Factitious diarrhea
Fecal impaction