Meconium Plug Syndrome
(Small Left Colon Syndrome)
Meconium plug syndrome is colonic obstruction caused by thick meconium. Diagnosis is based on radiographic contrast enema and sometimes testing for Hirschsprung disease. Treatment is radiographic contrast enema; surgical decompression is rarely required.
Meconium plug syndrome usually occurs in infants who are otherwise healthy. It is generally regarded as a functional immaturity of the colon, resulting in failure to pass the first stool.
Meconium plug syndrome is more common among
One study noted that 16% of cases of meconium plug syndrome were associated with magnesium tocolysis and only 3% were associated with Hirschsprung disease; however, other reports have noted Hirschsprung in 10 to 30% of infants with meconium plug syndrome.
Diagnosis of meconium plug syndrome is of exclusion and should be differentiated primarily from Hirschsprung disease.
Plain abdominal x-rays are nonspecific and can show signs of low intestinal obstruction. Conversely, contrast enema shows the characteristic appearance of the outline of the inspissated meconium against the wall of the colon, providing a double-contrast impression. Unlike meconium ileus, microcolon is not typically seen on x-ray with meconium plug syndrome.
The water-soluble contrast enema can be therapeutic by separating the plug from the intestinal wall and expelling it. Occasionally, repeated enemas are required.
Rarely, surgical decompression is required. Although most infants are healthy thereafter, diagnostic studies may be needed to rule out Hirschsprung disease or cystic fibrosis.