Chronic diarrhoea in children: A practical algorithm-based approach.

Diarrhoea is a leading cause of morbidity and mortality world-wide. Most diarrhoeal episodes are acute and infectious in origin. Diarrhoea lasting for longer than 4 weeks with no discernible infectious aetiology warrants thorough evaluation. The aim of this review is to elucidate an approach to evaluation of diarrhoea based on its pathophysiologic mechanisms with focus on aetiology, investigation and management of chronic diarrhoea. It includes a brief description of normal fluid homeostasis in the gut and pathophysiology of diarrhoea. Further, diarrhoea is classified as 'watery', 'fatty' and 'bloody' based on stool characteristics. Relevant history, physical examination findings, first and second-line investigations which help in differentiating the different types of diarrhoea are listed and an algorithmic approach to individual types of diarrhoea has been devised. Principles of management and recent advances in diagnostics and therapeutics of diarrhoea are briefly discussed.