A new born child has not passed meconium for 48 hrs. What is the diagnostic procedure of choice?

Ans is 'b' i.e. Contrast enema - Failure to Pass Meconium: Diagnosing Neonatal Intestinal Obstruction by VERA LOENING-BAUCKE, M.D., and KEN KIMURA, M.D. Timely passage of the first stool is a hallmark of the well-being of the newborn infant. 99% of term infants and 95% of premature infants pass meconium within 48 hrs of bih - Nelson 17/e p527. Failure of a full-term newborn to pass meconium within the first 24 hours should raise a suspicion of intestinal obstruction. It's usually a lower GI obstruction. In many cases of suspected neonatal intestinal obstruction, the clinical history and physical examination combined with plain abdominal radiographs, contrast enema radiographic examination, anorectal manometry and rectal biopsy eventually yield the diagnosis. Anal inspection is essential to exclude the presence of anal atresia, perinea] fistula with anal atresia and anal stenosis. In Hirschprung's disease barium enema radiographic examination, performed with the colon unprepared, may reveal a transition zone that separates the small- to normal-diameter aganglionic bowel from the dilated bowel above Meconium plug syndrome is the mildest and most common form of functional distal obstruction in the newborn. It is a transient form of distal colonic or rectal obstruction caused by inspissated, immobile meconium. Contrast enema is diagnostic, showing the outline of the meconium plug. In meconium ileus, low or distal intestinal obstruction results from the impaction of thick, tenacious meconium in the distal small bowel. Cystic fibrosis is the underlying disorder in most infants with meconium ileus. Contrast enema radiographic examination demonstrates a microcolon, often with no bowel contents. Reflux of contrast into the small bowel reveals the plugs. The small bowel is of narrow caliber below the plug and dilated above the plug. Small left colon syndrome is a condition with a characteristic caliber reduction in the sigmoid and descending colon unrelated to meconium inspissation or aganglionosis. Contrast studies show the colon to be shoened and to lack the usual touosity from the anus to the splenic flexure. A sharp transition zone is seen at the splenic flexure Other conditions associated with delayed passage of meconium are: Various maternal medical conditions can cause a delay in meconium passage. In addition, maternal drug use, such as illicit drugs, magnesium sulfate and ganglionic blocking agents, can affect the infant and interfere with the passage of meconium. Neonatal medical conditions that can be associated with a failure to pass meconium include - hypothyroidism, - hypercalcemia, - hypokalemia, - sepsis and - congestive hea failure.