[Chronic diarrhoea: Definition, classification and diagnosis].

Chronic diarrhoea is a common presenting symptom in both primary care medicine and in specialized gastroenterology clinics. It is estimated that >5% of the population has chronic diarrhoea and nearly 40% of these patients are older than 60 years. Clinicians often need to select the best diagnostic approach to these patients and choose between the multiple diagnostic tests available.