IBS is a functional disorder of the GIT characterised by chronic abdominal pain and altered bowel habits. It has no identifiable pathological process.

Demographics

• Female > male.
• Individuals aged 20 - 40.

Aetiology & Risk Factors

• Female.
• Young age.
• Mental health issues.
• Recent GIT infection and/or antibiotic use.

Pathophysiology

The pathophysiological processes leading to IBS are multifaceted and not yet fully understood. However, the most common findings associated with IBS are:

• Psychosocial factors, particularly early life stressors: Potentially a disorder of the gut-brain axis?
• GIT dysbiosis (bacterial overgrowth).
• Altered GIT motility.
• Altered GIT permeability.
• Visceral hypersensitivity/hyperalgesia.
• Food sensitivity.

Clinical Features:

Different patterns are seen in the presentation of IBS (subtypes can change and they have no long-term predictive value for the course of the disease):

• IBS-D: Diarrhoea dominant.