Hirschsprung Disease: A Review

Hirschsprung’s disease is a complex genetic disorder of the enteric nervous system which leads to functional intestinal obstruction, HD considered the most common cause of distal intestinal obstruction in the pediatric age group [1]. The disease named after Danish pathologist who credited with first description of clinical features of disease, [2] and he concluded erroneously that the pathology was in the proximal dilated bowel, after almost half-century Dr Swenson et al in his landmark paper (Hirschsprung’s disease: A new concept of the etiology) recognized the distal spastic rectum and colon are the site of obstruction [3]. since then different surgical techniques have been described all of them based on excision of the a ganglionic segment and anastomosis of the ganglionated bowel to the rectum, surgery is considered curative for most HD cases, It worth mentioning that the knowledge about congenital megacolon has been documented in prehistoric India nearly 4000 years before Harlod Hirschsprung, amazingly they referred the cause of the disease to defect in nerves and prescribed sigmoid colostomy as treatment for the disease [4]. The worldwide incidence of HD is 1:5000, [5] with Male: female ratio of 4:1, [6] the length of the diseased bowel affects M:F ratio till becoming almost the same 1.5:1 in total colonic aganglionosis [7]. HD grouped according to the length of the aganglionic segment which always start distally at the internal sphincter and extend proximally to variable distances, [5] which classified into short segment (rectosigmoid) which include 80% of HD patients, Total colonic aganglionosis which extends proximally at least the ileocecal valve but not >50cm of small bowel, the long segment category is located between the previous 2 categories, and finally Zuezler syndrome (very-long-segment) which extends for >50cm of small bowel, [7,8] the ultra-short segment now replaced by the internal anal sphincter achalasia, which is more accurate for pathologic entity [9].