Hirschsprung disease

Hirschsprung disease is a congenital absence of enteric ganglion cells causing functional obstruction . Diagnosis rests on rectal biopsy demonstrating absent ganglion cells, hypertrophic nerves (>40 microns), and abnormal acetylcholinesterase staining [e3187-c14, e933-c23]. Contrast enema shows a transition zone in 75–80% of cases, but false-negative rates reach 20–25% and concordance with pathology is only 62% overall—worse (25%) for long-segment disease [e733-c7, e733-c10, e733-c12]. Rectal irrigations with large-bore catheter (20 Fr) and 10–20 cc aliquots are the cornerstone of preoperative management; stasis without irrigation leads to bacterial translocation and enterocolitis [e933-c1, e933-c6]. The transanal Swenson is preferred for rectosigmoid disease because it leaves minimal aganglionic tissue, but laparoscopic mobilization to the pelvic floor reduces sphincter stretch and morbidity [e933-c13, e1000-c12]. Dissection must start ≥1 cm above the dentate line; injury to the dentate or overstretching sphincters causes incontinence [e933-c20, e933-c19]. For transition zones proximal to the splenic flexure, await permanent sections and perform ileostomy rather than relying on frozen section . Postoperative feeding is delayed until the abdomen is soft and an X-ray confirms decompression, typically 3–4 days, to prevent enterocolitis [e933-c28, e933-c29]. Enterocolitis—the life-threatening complication—presents with distension, fever, and diarrhea or obstipation; treatment includes resuscitation, rectal irrigations, and IV metronidazole [e3187-c28, e3801-c7, e3801-c8]. Long-term, 30% of patients experience enterocolitis and 80% require laxatives; most with rectosigmoid disease achieve continence by school age [e1068-c22, e3187-c30, e3187-c31].