#may2020amc1
A 48 hour term, male infant presents with a 12 hour history of green vomiting. The parents state that there have been some wet nappies but that the child has not opened his bowels since birth. The abdomen is distended, full but not tense and not tender. The anus is normally sited. Which one of the following is the most useful diagnostic test?
A. Blood cultures
B. Lower gastrointestinal contrast study
C. Suction rectal biopsy
D. Ultrasound scan
E. Upper gastrointestinal contrast study
Explanatory Notes:
The clinical history at this age and with the triad of bile vomiting, abdominal distension and failure to pass meconium points to a likely diagnosis of Hirschsprung's disease. The diagnostic test is therefore a suction rectal biopsy to look for an absence of ganglion cells.
The normally sited anus rules out an anorectal anomaly.
Suction rectal biopsy - correct. Upper gastrointestinal contrast study - the presence of bile vomiting may lead the candidate to consider malrotation and volvulus but typically children with malrotation have passed meconium. If this is felt to be ambiguous then an alternative answer option would be plain abdominal x-ray - this would lead you to upper or lower GI obstruction but not to the underlying cause without further
investigation
Blood cultures - sepsis is a possible cause but less likely
Lower gastrointestinal contrast study - lower GI contrast can be used to investigate lower GI obstruction but will not prove a diagnosis of Hirschsprung's disease
Ultrasound scan - USS is unlikely to be contributory here
A 48 hour term, male infant presents with a 12 hour history of green vomiting. The parents state that there have been some wet nappies but that the child has not opened his bowels since birth. The abdomen is distended, full but not tense and not tender. The anus is normally sited. Which one of the following is the most useful diagnostic test?
A. Blood cultures
B. Lower gastrointestinal contrast study
C. Suction rectal biopsy
D. Ultrasound scan
E. Upper gastrointestinal contrast study
Explanatory Notes:
The clinical history at this age and with the triad of bile vomiting, abdominal distension and failure to pass meconium points to a likely diagnosis of Hirschsprung's disease. The diagnostic test is therefore a suction rectal biopsy to look for an absence of ganglion cells.
The normally sited anus rules out an anorectal anomaly.
Suction rectal biopsy - correct. Upper gastrointestinal contrast study - the presence of bile vomiting may lead the candidate to consider malrotation and volvulus but typically children with malrotation have passed meconium. If this is felt to be ambiguous then an alternative answer option would be plain abdominal x-ray - this would lead you to upper or lower GI obstruction but not to the underlying cause without further
investigation
Blood cultures - sepsis is a possible cause but less likely
Lower gastrointestinal contrast study - lower GI contrast can be used to investigate lower GI obstruction but will not prove a diagnosis of Hirschsprung's disease
Ultrasound scan - USS is unlikely to be contributory here
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