A 4 year old boy presents with a history of constipation since the age of 6 months. His stools produced every 3-4 days are describe as large and hard. Physical examination is normal, rectal examination reveals alarge ampulla, poor sphincter tone, and the stool in the rectal vault.

The most Likely DX (Diagnosis) is?

A- Functional Constipation
B- Intestinal Obstruction
C- DOCpulaski chicken bucket
D- Hirschprug disease
E- Hypothyroidism