For a neonate at 48 hours of birth with a history of non-passage of meconium, next step in evaluation will be:
**Core Concept**
The non-passage of meconium in a neonate can indicate intestinal obstruction, ileus, or other gastrointestinal disorders. The evaluation of this condition involves a stepwise approach, starting with a detailed physical examination and medical history, followed by imaging studies and laboratory tests.
**Why the Correct Answer is Right**
The next step in evaluation would be to perform an abdominal radiograph (X-ray) to assess for the presence of air-fluid levels, dilated bowel loops, or other signs of intestinal obstruction. This imaging study can help differentiate between various causes of non-passage of meconium, such as ileus, atresia, or Hirschsprung's disease. The abdominal X-ray is a quick and non-invasive test that can provide valuable information for further management.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because performing an ultrasound would not be the immediate next step in evaluation, although it may be useful later in the diagnostic process.
**Option B:** This option is incorrect because a rectal examination, while useful for assessing the anorectal angle and presence of stool, would not provide the necessary information for a definitive diagnosis of intestinal obstruction or other causes of non-passage of meconium.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that the non-passage of meconium in a neonate should prompt a thorough evaluation, including a detailed medical history, physical examination, and imaging studies. Early recognition and treatment of intestinal obstruction or other gastrointestinal disorders can significantly improve outcomes for these vulnerable patients.
**Correct Answer: C.** Abdominal radiograph (X-ray)