The objective of the multi-centre study conducted in six departments in the Czech Republic was to assess the gut permeability of the gut in patients with inflammatory bowel diseases. The investigations comprised 135 patients, incl. 69 with Crohn’s disease and 66 patients with ulcerative colitis, 70 men and 65 women, mean age 35.6 years who were submitted to a total of 435 examinations. Intestinal permeability was examined by means of a test with lactulose, mannitol and D-xylose with 5-hour urine collection in which all sugar levels are examined by means of capillary gas chromatography and compared with the activity of the disease, haematological and biochemical parameters, and the role of the index of intestinal permeability as a predictor of relapse is evaluated. The value of intestinal permeability does not differ in patients with Crohn’s disease and ulcerative colitis in the quiescent stage from healthy volunteers. In patients in the active stage of the disease the intestinal permeability differs significantly from the quiescent stage, and in patients with Crohn’s disease it correlates positively with inflammatory markers and inversely with the haemoglobin level and hematocrit and nutritional indicators. The index of permeability of the gut LAMA serves as a predictor of relapse in patients with Crohn’s disease – with a sensitivity of 66.7% and specificity of 92.9%, the positive predictive value is 85.7% and the negative predictive value 81.3%.

        Key words: intestinal permeability – lactulose – mannitol – xylose – inflammatory bowel disease – Crohn’s disease – ulcerative colitis