|Functional gastrointestinal disorder|
|Other names||Disorders of gut–brain interaction|
Functional gastrointestinal disorders (FGID), also known as disorders of gut–brain interaction, include a number of separate idiopathic disorders which affect different parts of the gastrointestinal tract and involve visceral hypersensitivity and motility disturbances.
Terms such as functional colonic disease (or functional bowel disorder) refer in medicine to a group of bowel disorders which are characterised by chronic abdominal complaints without a structural or biochemical cause that could explain symptoms. Other functional disorders 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 functional gastrointestinal disorders. 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 disorders
B. Gastroduodenal disorders
C. Bowel disorders
D. Centrally mediated disorders of gastrointestinal pain
E. Gallbladder and sphincter of Oddi disorders
F. Anorectal disorders
G. Childhood functional GI disorders: Neonate/Toddler
H. Childhood functional GI disorders: Child/Adolescent
Functional gastrointestinal disorders are very common. Globally, irritable bowel syndrome and functional dyspepsia alone may affect 16–26% of the population.
There is considerable research into the causes, diagnosis and treatments for FGIDs. Diet, microbiome, genetics, neuromuscular function and immunological response all interact. A role for mast cell activation has been proposed as one of the factors.
It is well established that mast cell activation can generate epithelial and neuro-muscular dysfunction and promote visceral hypersensitivity and altered motility patterns in FGIDs, postoperative ileus, food allergy and inflammatory bowel disease.
Mast cells and CD3+ T cells are increased in colonic biopsies of patients with IBS vs non-inflamed controls