Semiquantitative assessment of breath hydrogen testing

Background and Aim: A major use of breath hydrogen testing is to assess absorptive capacity for sugars to assist dietary design for management of gut symptoms. Qualitative reporting takes no account of the vigor of hydrogen response and provides little insight into degrees of malabsorption. This study aimed to describe a semiquantitative reporting method and to compare results with those reported qualitatively. Methods: In consecutive Caucasian patients with Crohn s disease (n=87), ulcerative colitis (59), functional gastrointestinal disorders (FGID) (162), and healthy controls (76), area under the curve was calculated for lactulose (15g). This was compared with that for lactose (50g) and fructose (35g). Degree of malabsorption was categorized into arbitrary groups. Results: Semiquantitative results for =30 (designated convincing ) malabsorption was most similar to those using a qualitative cutoff value of 20ppm, but in 38 and 21 of patients, the classification of malabsorption (nil or clinically significant) changed for fructose and lactose, respectively. Using a cutoff of 10ppm, 49 and 5 were classified differently. Crohn s disease had a higher prevalence (42 ) of convincing fructose malabsorption than controls (24 ) or patients with FGID (33 ) (P