Hirschsprung's disease results from failure of neural crest cell migration. The RET proto-oncogene mutation accounts for 50% of familial cases. The most common form involves absence of ganglia in the:

• A Entire colon and terminal ileum (total colonic aganglionosis)
• B Descending colon only
• C Transverse colon and splenic flexure
• D Rectosigmoid region (80% of cases) ✓

Explanation

In Hirschsprung's disease, aganglionosis begins at the internal anal sphincter and extends proximally to varying lengths: rectosigmoid accounts for ~75–80%, followed by longer segment (10–15%), total colonic (5%), and ultra-short segment (<1%). Pull-through operations (Swenson, Soave, Duhamel) pull the ganglionic bowel down to the anus, with laparoscopic-assisted pull-through now favoured. RET mutations are found in both sporadic (15–35%) and familial (50%) cases.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.