This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
[{'content': 'A male infant presented with distension of abdomen shortly after birth with the passing of less meconium. Subsequently, a full–thickness biopsy of the rectum was performed. The rectal biopsy is likely to show – \nSelect and explain. \nA. Fibrosis of submucosa, B. Lack of ganglion cells, C. Thickened muscularis propria, D. Hyalinisation of the muscular coat', 'role': 'user'}, {'content': 'Answer: B \nExplanation: "Whenever neonate presents with delayed passage of stool, Hirschsprung\'s disease should be suspected".\nDiagnosis of Hirschsprung\'s disease\n\nThe diagnosis of Hirschsprung\'s disease is confirmed by rectal suction biopsies\nRectal suction biopsies demonstrate —\n\n\nHypertrophied nerve bundles\nThe absence of ganglion cells\n\nOther diagnostic procedures in Hirschsprung\'s disease\nRectal manometry\nAnorectal manometry measures the pressure of internal anal sphincter while a balloon is distended in the rectum. The results are interpreted as —Normal individual → Reflex decline in internal sphincter pressure.\nHirschsprung\'s disease → Pressure fails to drop, the Paradoxical rise in pressure with rectal distention.\nRadiography (Barium enema)\nIt demonstrates the presence of the transition zone between the normal dilated proximal colon and a smaller calibre obstructed distal colon caused by non-relaxation of aganglionic bowel.\nDelayed passage of stool (meconium) and abdominal distension suggests low intestinal obstruction.', 'role': 'assistant'}]