Hirschsprung’s disease is a serious childhood disease which affects boys more frequently. Its cause is agenesis of ganglion cells of the affected portion of the gut, most frequently the rectum or rectosigmoid, rarely the colon. The aganglionic portion is permanently contracted and causes mechanical obstruction of the gut. A serious complication of the disease is ischaemic enterocolitis. In case of an acute course of the disease a native X-ray of the abdomen is indicated which not infrequently reveals an advanced ileous condition. In order to assess the correct diagnosis and to assess the length of the aganglionic segment irrigography is the decisive method. In typical cases the rectosigmoid index is less than 1. In case of a suspected short aganglionic segment close to the anus a defaecogram is indicated. The diagnosis of Hirschsprung’s disease is supported by the absence of the rectosphincteric reflex and delayed evacuation of the colon. Total aganglionosis is suggested by general shortening of the colon without the usual winding and marked reflux into the terminal loops of the ileum. Falsely negative findings are as a rule caused by a poor examination method or a less typical irrigographic image. The cause of falsely positive findings are most frequently expansive processes in the region of the lesser pelvis.

        Key words: Hirschsprung’s disease - megacolon congenitum - constipation