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Meconium Plug Syndrome

(Small Left Colon Syndrome)


William J. Cochran

, MD, Geisinger Clinic

Last full review/revision May 2020| Content last modified May 2020
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Meconium plug syndrome is blockage of the large intestine with thick intestinal contents (meconium).

  • Meconium plug syndrome may result from Hirschsprung disease or cystic fibrosis.

  • Typically, newborns have feeding problems, vomit, have an enlarged abdomen, and do not have a bowel movement during the first day or two of life.

  • The diagnosis is based on symptoms and x-ray results.

  • The blockage is treated with enemas and sometimes surgery.

Meconium, a dark green material, is a newborn's first stool. Newborns expel meconium at or shortly after birth. If the meconium is abnormally thick or tarlike, it can block the large intestine (colon). In meconium plug syndrome, the colon is completely blocked with thick meconium. Above the blockage, the small intestine is enlarged (dilated) resulting in abdominal swelling (distention).

Meconium plug syndrome usually occurs in infants who are otherwise healthy, but it is more common among premature infants, infants born to diabetic mothers, and infants of mothers who were given magnesium sulfate to treat preeclampsia, eclampsia, or preterm labor.

Meconium plug syndrome may be a sign of other disorders, such as Hirschsprung disease or cystic fibrosis. Meconium ileus is similar to meconium plug syndrome except that it is the small intestine that is blocked by meconium.

Symptoms of Meconium Plug Syndrome

After birth, newborns usually pass meconium in the first 12 to 24 hours. However, newborns with meconium plug syndrome do not pass meconium within the first day or two and also have symptoms of intestinal blockage, including vomiting and abdominal swelling. Doctors may feel enlarged loops of small bowel through the abdominal wall.

Diagnosis of Meconium Plug Syndrome

  • Plain x-rays of the abdomen

  • Radiopaque contrast enema

  • Sometimes testing for Hirschsprung disease

Doctors suspect meconium plug syndrome in newborns who have symptoms of blockage and do not pass meconium within the first day or two. Plain x-rays of the abdomen may show intestinal obstruction. To make a definitive diagnosis, doctors take x-rays after giving an enema using a liquid substance that is visible on x-rays (radiopaque contrast agent). The contrast agent outlines the inside of the colon and allows doctors to see the meconium plug.

Infants who have meconium plug syndrome are often tested for Hirschsprung disease and for cystic fibrosis.

Treatment of Meconium Plug Syndrome

  • Radiopaque contrast enema

  • Rarely surgery

The radiopaque contrast enema is used to help diagnose and treat meconium plug syndrome. The contrast liquid helps bring fluid into the colon and break off the meconium so that the infant can then pass the meconium.

If the enema does not remove the plug, doctors may remove it surgically.

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