Abstract : Chronic diarrhoea is a frequent clinical presentation in our population. It may correspond to many gastro-intestinal or systemic pathologies. Most frequent causes are irritable bowel syndrome, functional intestinal disorders or lactose intolerance, but organic diseases have also to be searched. Focused patient questioning and some specific aspects of clinical examination play a key-role in diagnosis orientation and the use of complementary explorations. The present paper proposes a structured diagnostic procedure aiming at an optimal use of complementary explorations.