ABSTRACT
Hydrogen level in the exhaling air after oral lactose or glucose loading was determined in normal subjects and patients after gastreetoaiy. Basal hydrogen was less than 30 ppm in all the 16 normal subjects. After lactose ingestion, 13 subjects out of the 16 (81.2%) showed an increass of hydrogen excretion of 20 ppm or more. The average peak time of hydrogen accretion was in the 3.25 hours after lactose ingestion. After glucose ingestion,the increase of hydrogen excretion was less than 20 ppm. In 7 patients with Billroth I gastrec- tomy and 14 patients with Billroth II gastrectomy, increase of hydrogen excretion after lactose ingestion occurred in 6 out of the 7 (85.7%) and 12 out of the 14 (85.7%) respectively, which is not significantly different from that of the control. After glucose intake, increase of hydrogen excretion occurred in 1 out of the 7 (14.2%) and 5 out of the 14 (35.7%). The elevation of hydrogen in the exhaling air indicates the overgrowth of bowel bacteria. Our findings suggest that hydrogen breathing test after lactose loading is insensitive to reveal this phenomenon in patients after gastrectomy, but after glucose loading, the test might carry out this function especilly in those with Billroth II operation.