A functional bowel disorder - No identifiable disease underlying the Sx - Sx are as a result of abnormal functioning of a normal bowel

No longer a ‘diagnosis of exclusion’

Epidemiology:

• It is very common and occurs in up to 20% of the population
• It affects women more than men
• more common in younger adults

Aetiology

No structural explanation - seems to involve smooth muscle activity +/- visceral hypersensitivity.

A reduction in PNS. activity and an increase in SNS activity is seen in many IBS patients

Possible inflammatory link, can be triggered by infections, Abx can improve or worsen IBS.

Factors that can trigger the onset of IBS:

• affective disorders e.g. depression, anxiety
• psychological stress and trauma
• GI infection
• Antibiotics
• eating disorders

PC