Validation of the use of a tube with a proximal occlusive balloon for measurement of intestinal absorption in man.

Because of its simplicity, a tube with a proximal occlusive balloon is widely used to measure segmental intestinal absorption in man. Yet, the possibility that the presence of an inflated balloon might alter the absorptive capacity of the underlying segment of intestine has never been tested. In the present work the jejunal absorption of water and ions has been measured in 13 healthy subjects with the proximally occlusive tube and with the triple lumen nonocclusive method; precautions were taken to achieve similar flow rate and ionic composition of the fluid entering the test segment with both techniques in each subject. Under these conditions net water and ion movements measured by the two methods were identical. This finding validates the use of the proximal occlusive tube to measure intestinal absorption in man.