Introduction. The congenital absence of nerve ganglia in the intermuscular and submucosal nerve plexuses of the colon in Hirschsprung’s disease leads to impaired motility and the risk of intestinal obstruction. Most often, Hirschsprung’s disease diagnosis is put in the neonatal period or in early childhood. Rare cases of late diagnostics may be associated with a blurred clinical picture, as well as with delay in histological verification of aganglionosis.
 Clinical observation. This clinical observation describes a case of 17-year-old patient who was admitted to the surgical department with complaints on the lack of independent stool, a large fecal stone, abdominal pain. The patient could not have the self-emptying stool since her birth. Conservative therapy had only a partial positive effect. Irrigography findings caused a suspicion on agangliosis pathology of the rectosigmoid colon; however, histological verification of the diagnosis has never been made. Immunohistochemical examination of bioptats of the rectal mucous for calretinin had confirmed the Hirschsprung’s disease, and the first stage of surgical treatment was performed – resection of the sigmoid colon section with a fecal stone and descendostomy formation. Radical surgery was postponed because of patient’s pregnancy.
 Conclusion. Late diagnosis of Hirschsprung’s disease is still a problem even in classical forms of the disease. It is important to be alert in older children and adults with a history of long-lasting constipation. Morphological examination of the neural ganglia of the colon is a key point in verifying the diagnosis.