College of Science ,University of Mustansiriyah discussed a master dissertation on evaluating of histopathological and immunohistochemical changes of newborn intestinal biopsy for the diagnosis of Hirschsprung's disease by the postgraduate student, Mrs. Russell Abbas Abd Al-Hussein.

The dissertation aimed at evaluating the histopathological and immunohistochemical changes that occur in the intestinal layers of newborns and infants who suffer from chronic constipation and detecting differences that may occur in blood cells and compare them with non-infected children.

The dissertation highlighted conducting a histological analysis using hematoxylin and eosin stain, performing standard histological examinations of rectal tissues, using toluene blue to count the number of mast cell  and calretinin to investigate ganglion cells.

The dissertation concluded that the immunochemical study of carretinin is the most accurate in the diagnostic process, as well as increasing in the number of mast cells and thickening of the intestinal layers in infected patients.