[Diarrhea in immune deficiency status]

With a prevalence of approximatively 50%, diarrhoea is a frequent event in immune deficiency of any cause. Because this condition is permanent in AIDS, the main characteristic of diarrhoea is chronicity. Non infectious causes are more common in conditions other than AIDS with, for exemple, intestinal injuries related to graft versus host disease or to chemotherapy toxicity. Among infectious causes, enteric parasitic diseases such as cryptosporidiosis or microsporidiosis are more commonly observed in the immunodeficiency related to HIV while viral infections due to cytomegalovirus or adenovirus seem possible in any case of severe troubles of the immunity. Gram-negative infections and Clostridium difficile colitis have to be diagnosed because efficient treatment is available. In these patients usually in bad general condition, because diarrhoea is often of unknown aetiology or non curable, the diagnostic and therapeutic strategy has to be pragmatic in order to control the symptoms without an excess of invasive procedures.