Duodenal intubation with secretin stimulus for diagnosis of giardiasis.

The use of secretin to facilitate the demonstration of Giardia lamblia in duodenal juice was studied in children under investigation for chronic diarrhoea. 30 children aged 3 months to 13 years, whose stools were negative for G. lamblia, were studied. G. lamblia was demonstrable in a sample of duodenal juice in 1 of the 30 children before an intravenous injection of secretin (1 or 2 mg/kg), but in 9 of the 30 children after secretin. It is concluded that examination of duodenal juice after secretin stimulus is an effective method of showing giardial infestation.