Irritable Bowel Syndrome

Irritable Bowel Syndrome (IBS) is a functional gastrointestinal disorder characterized by chronic abdominal pain associated with altered bowel habits, in the absence of detectable structural or biochemical abnormalities.

Definition

Irritable Bowel Syndrome (IBS) is a functional gastrointestinal disorder characterized by chronic abdominal pain associated with altered bowel habits, in the absence of detectable structural or biochemical abnormalities.

Epidemiology

Global prevalence: approximately 10–15% of the population
More common in women than men (2:1 ratio in Western countries)
Typically presents in late teens to early adulthood
Symptoms can be chronic and relapsing, often triggered by stress or diet
Significant impact on quality of life and healthcare utilization

Etiology

Exact cause unknown; multifactorial
Altered gut motility and visceral hypersensitivity
Gut-brain axis dysregulation: abnormal communication between CNS and enteric nervous system
Post-infectious IBS following gastroenteritis
Altered gut microbiota composition
Psychosocial factors: stress, anxiety, depression
Dietary triggers: high FODMAP foods, caffeine, alcohol

Pathophysiology

Increased intestinal sensitivity to distension (visceral hypersensitivity)
Altered motility: diarrhea-predominant, constipation-predominant, or mixed
Low-grade intestinal inflammation in some cases
Gut microbiota dysbiosis contributes to symptoms
Abnormal CNS processing of gut signals leads to enhanced pain perception