Idiopathic intestinal inflammations in children and adolescents are chronic affections of the small intertine and the colon of unknown etiology. The results of long-term therapy are not always favorable and we frequently encounter its undesirable effects. Of great significance is therapy with immunosuppressive drugs and biological treatment. In the majority of patients diagnosis is made at a relatively early age when there is apparent the big effect the disease has on common activities and productivity as well as on the patients' attitudes, doubts and faith in recovery. Therefore, a correct and early diagnosis is very important, being very difficult in view of the uncharacteristic clinical manifestations of this ailment. At present, an undoubted contribution is the application of the radio-isotope method of leucoscintigraphy which is described in connection with two case reports.

        Key words: Crohn's disease - colitic ulcerosa - children and adolescents - scintigraphy with 99mTc-tagged leucocytes.