Hard Stools Every 5–7 in Pediatrics — 4yo Child | Pediatric Gastroenterology | SMLE Q#11439

A 4-year-old boy has constipation since infancy with hard stools every 5–7 days, marked straining, and progressive abdominal distension. He has intermittent foul-smelling watery stool that soils his underwear despite adequate fluids, high-fiber diet, and daily stool softeners. Height and weight are at the 10th percentile. Abdominal examination shows moderate distension. Digital rectal examination finds an empty rectum, followed by a sudden passage of stool and gas after withdrawal. A contrast enema shows a distal narrowed segment with proximal colonic dilatation. What is the most appropriate next step in management?