[Hydrogen (H2) breath tests in the diagnosis of small intestine diseases]

We have applied the ion sensitive analysis of hydrogen (H2) in expired air in intervals of five minutes for five hours to determine carbohydrate malabsorption. In 19 patients with lactose malabsorption the increase in hydrogen was prior (45, SE 13 min) to healthy volunteers (142, SD 71 min, p less than 0.01). In comparison to blood glucose with the breath test no false positive results were observed. D-xylose absorption measured by breath test and renal excretion for five hours was determined in 24 volunteers and 12 patients with various intestinal diseases. There was a good correlation between both methods. In all patients the area under the concentration-time-curve was elevated (2077, SD 1260 ppm H2/5h) compared to healthy volunteers (434, SD 271 ppm H2/5h, p less than 0.01). Small bowel transit time was determined by ingestion of lactulose. In 32 healthy persons transit time was 85, SD 19 min. In 10 patients an early increase in hydrogen indicated bacterial overgrowth in the small bowel while 14C-Cholylglycine-breath test was abnormal in only six patients. The hydrogen breath test measured by ionsensitive mode is noninvasive, well tolerated, semiquantitative, and ideally suited for screening of intestinal disorders.