Tryptic activity in the duodenal aspirate following a standard test meal in giardiasis.

Following a standard test meal, tryptic activity was measured in the duodenal aspirate in 26 cases of giardiasis. Twenty normal subjects were studied to serve as controls. The mean of tryptic activity values in the control and giardiasis group was 17.1 muEq/min/ml (S.D. +/- 1.4) and 12.3 muEq/min/ml (S.D. +/- 6.9) respectively. The difference in the two groups was highly significant (p less than 0.01). Out of 10 patients who showed decreased tryptic activity, 9 were restudied after eradication of the parasite and the tryptic activity returned to normal in all of them. The post treatment values were significantly higher than the pretreatment values (p less than 0.01).