RESUMO
Fifty-five Thai patients with chronic diarrhoea were prospectively studied to find out the underlying causes. The aetiology was identified in 38.2%, uncertain in 29.1%, and unknown in 32.7% of the patients. In the group with a definitive aetiologic diagnosis, parasitic and infective causes were commoner than non-infective causes. Amoebiasis and giardiasis were more frequent than expected, such that empirical therapeutic trial with an antiprotozoal may be justified if initial routine investigations fail to uncover the cause of the diarrhoea. No significant clinical features were noted between the infective and the non-infective groups. Overall, repeated stool microscopy using the concentration technique was the most useful single investigation in approaching the chronic diarrhoea problem.