Hirschsprung's disease occurs rarely and sporadically in adult, involving males. In cases, which are manifested perinatally, the so called Hirschsprung-associated congenital anomalies (mainly central nervous system, urogenital and cardiovascular) may present (2-21%), which have not observed in adult. Mental retardation and Hirschsprung's disease more frequently are associated with Down syndrome (5-10%). The discoveries of molecular genetics in the last 4-5-years through the examination of transgenic ("knockout") mice, proved the basic role the mutation of 4 genes: the RET (receptor tyrosin kinase), a proto-oncogene, coding its ligand, the glial cell-line derived neutrophic factor (GDNF), the gene of the endothelin-B receptor (ENDRB) and the gene one of its ligand, the endothelin-3 (EDN3), in the pathogenesis of Hirschsprung's disease. In our case, the short segment Hirschsprung's disease caused respiratory and cardiac failure, which was recognized by autopsy. Besides, the severe mental retardation, the role of the long term use of antipsychotic medicines comes up in the prolongation and masking of the symptoms. The accompanied mental retardation and microcephalia in early childhood are known, which are associated anomalies with Hirschsprung's disease. In cases of Hirschsprung diseases at adults, no other associated congenital anomalies has been published. The mental retardation in Down-syndrome, in association with Hirschsprung's disease (and presumable in our case, too) is supposed to be the consequence of the mutation in the gene of GDNF. In this case, we observed, that the so called short segment H-d was accompanied at a 33 years old men patient with mental retardation (who was originated from a gypsy ethnic minority), because of it the connection of the nurses and the patient was disturbed and the main symptom of the H-d (chronic obstipation) remained hidden. The mechanic ileus was going on behind the scenes, and in addition to the cardiac failure caused the death of the patient. Practical conclusion of the case is that, Hirschsprung's disease should be suspected in all adult patients, who had severe obstipation persisting since childhood, especially in males.