19th July 2023

Definition and Pathophysiology

FBDs are a group of conditions characterised by chronic GI tract symptoms for which no pathology can be found by conventional testing means. While previously defined as “lacking organic cause”, research has now demonstrated a correlation with abnormal gut-brain communications. This occurs secondary to abnormalities in GI motility, visceral hypersensitivity, altered mucosal and immune function, altered gut microbiota, and altered CNS processing. Risk factors include female gender, adolescents/young adults, and concomitant chronic psychiatric conditions (e.g., anxiety, depression, OCD), chronic pain syndromes (e.g., fibromyalgia) or functional conditions (e.g., chronic fatigue syndrome). They are the most commonly encountered GI pathologies in both primary and secondary care, therefore, it is important to recognise, diagnose and treat early.