The etiology of Crohn's disease remains unknown, one of theories is the damage of bowel wall with the impairment of small bowel barrier. In patients with Crohn's disease was found high level of small bowel permeability in dependence of disease activity. The aim of our study was to measure small bowel permeability in first-degree relatives of the patients with Crohn's disease. In 14 first-degree relatives of Crohn's disease patients (7 men, 7 women) there was measured small permeability using lactulose, mannitol and D-xylose. Sugars were investigated in 5 hour collected urine and examined using capillary gas chromatography. The absorption of all the sugars--lactulose, mannitol and D-xylose did not differ from healthy controls. The small bowel permeability index (lactulose/mannitol) did not differ from healthy controls too (0.023 vs. 0.019, p = 0.451). These preliminary results confirms the theory, that there is no damage of small bowel barrier in first degree relatives of Crohn's disease patients.

Keywords: Adult; Child; Crohn Disease /genetics/; Female; Humans; Intestine, Small /physiopathology/; Lactulose; Male; Mannitol; Permeability; Xylose