COMPARISON OF SCINTIGRAPHY AND LACTULOSE BREATH HYDROGEN TEST FOR ASSESSMENT OF OROCECAL TRANSIT - LACTULOSE ACCELERATES SMALL-BOWEL TRANSIT

The lactulose breath test (LET) and gastroenterocolonic scintigraphy ( GECS) can both be used to measure orocecal transit time (OCTT). The ai ms of this study were (1) to measure OCTT by LET and GECS and (2) to d etermine whether lactulose alters orocecal transit. Methods: Eight nor mal subjects underwent simultaneous breath hydrogen testing, GECS, and duodenal manometry while receiving either 10 g lactulose or placebo w ith a radiolabeled solid/liquid test meal during two studies. There wa s a good correlation between OGTT by LET and GECS when performed simul taneously (r = 0.95; P < 0.001). OCTT by GECS with lactulose was signi ficantly faster (P = 0.004) than by GECS without lactulose, despite no change in gastric emptying of liquids and slowing of gastric emptying of solids (P = 0.02). The postprandial duodenal motility index was gr eater with lactulose than with placebo (P = 0.031). This study demonst rates that LET and GECS (without lactulose) are not equivalent measure s of OCTT. The standard LET accelerates OGTT and slows gastric emptyin g. Therefore, lactulose has a direct accelerating effect on small inte stinal transit.