ABSTRACT
Chronic diarrhoea is a common complication in HIV-infected patients. With an overall frequency of 30to 90. In the majority of cases a specific pathogen can be identified; but in 15-35of patients the diagnostic evaluation is unrewarding. Although many explanations have been proposed; the mechanisms of cryptogenic diarrhoea remains still uncertain. A stepwise diagnostic work-up is generally recommended; but the necessity of performing invasive procedures; such as gastrointestinal endoscopy and co-lonscopy; is contraversial stoll studies however; do not permit the detection of all treatable pathogens. Thus; for patients with persistent diarrhoea whose stool cultures and parasitologic examination are negative a comprehensive diagnostic evaluation seems advisable. From January 1990 to December 1992; we observed 130 patients with chronic diarrhoea out of a total of 374 AIDS patients (34.8). Enteric pathogens were identified in 90 patients (69.2). The frequency distribution was as follows: Cryptosporidium spp 68.9; Giardia lambia 21.1. Cryptomegalovirus 13.3; Salmonella ssp. 10; Mycobacterium avium complex 3.3; Isospora belli 2.2; Clostridium difficile 2.2. Mixed infections were present in 13.1of patients. The pathogenic role of Microsporidia however; could not be evaluated since electron microscopic examination was not performed in all cryptogenic cases. specific treatment is always preferable to empiric antimicrobial therapy; considering the variety of infectious agents and the high incidence of mixed infections. Patients with diarrhoea due to pathogens for which effective antimicrobial treatment is lacking and refractory to anti-motility agents may benefit from therapy with somatostatin analogues; although temporarily