Meconium Plug

Condition: Meconium Plug

Overview (“What is it?”)

  • Definition:  Meconium plug is a condition in some newborn infants where the large intestine (colon) is blocked by solid pellets of meconium. “Meconium” is the term used for the stool that collects in the intestines of fetuses (unborn babies). In some babies the stool becomes solidified into hard pellets, causing blockage of the colon.
  • Epidemiology: 
    • The underlying cause meconium plugs is largely unknown.
    • A subset of infants with meconium plugs may have Hirschsprung disease (condition where nerves controlling the motility of the intestines) and cystic fibrosis (disease where thick mucus in the lungs and intestines can cause life-long problems), so these diseases should be ruled out. 
    • It occurs equally in males and females.

Signs and Symptoms (“What symptoms will my child have?”)

  • Signs:  The newborn does not pass meconium in the first 24 hours of life. There may be swelling of the belly, feeding intolerance and vomiting. 

Diagnosis (“What tests are done to find out what my child has?”)

  • Labs and tests:  When a newborn does not pass meconium, a work-up is started.
    • Bloodwork is sent to look for infections, abnormalities in levels of minerals (electrolytes)
    • X-rays:  Plain X-rays may give clues as to the cause of intestinal blockage.
    • Contrast enema:  Water-soluble contrast is instilled through the anal opening and x-rays are obtained to see the anatomy of the large intestine and where the blockage may be. If meconium plugs are present in the colon, contrast mixes with the pellets and allows the stool to be evacuated.
  • Conditions that mimic this condition:  Hirschsprung disease, cystic fibrosis, intestinal atresia, small left colon syndrome (seen in infants of mothers with diabetes), infants whose mothers may have required medicine (magnesium) to stop premature labor, and other causes of newborn bowel obstruction. 

Treatment (“What will be done to make my child better?”)

  • Contrast enema:  Contrast enema helps in both the diagnosis and treatment of meconium plugs. Sometimes, if there are lots of plugs present, repeating the contrast enema may be necessary to clear the intestine of all the plugs.
    • The symptoms are relieved and the infant begins to eat and stool normally. 
    • During the time the newborn is not eating or stooling normally, s/he will be cared for in the neonatal unit. S/he will receive intravenous fluids and may occasionally need nutrition given by vein (total parenteral nutrition or TPN). If s/he is vomiting or the belly is really swollen, a nasogastric tube may be placed into the stomach to drain air and fluid. 
  • Surgery:  Surgery is not needed for meconium plug syndrome.
    • In these babies, it is important rule out Hirschsprung disease. Infants with Hirschsprung disease do not have normal nerves in the rectum so the intestine does not allow stool to pass normally. Hirschsprung disease is ruled out by a suction rectal biopsy.
      • Suction rectal biopsy:  A suction rectal biopsy is the definitive test for Hirschsprung disease. This is usually done at the bedside of the baby and does not require anesthesia. In this procedure, a small instrument (size is slightly larger than a rectal thermometer) is inserted about 2 centimeters into the anal opening. Gentle suction is applied, pulling the rectal lining into the instrument. A small piece of the rectal lining is cut. Three such samples are obtained and sent for microscopic analysis. The pathologist examines the specimens for presence of normal nerves.
      • Risks of suction rectal biopsy include bleeding, getting a hole in the intestine and not obtaining adequate specimens.

Home Care (“What do I need to do once my child goes home?”)

  • Diet:  Normal diet for age.
  • Activity:  No limitations.
  • What to call the doctor for:  Call for persistent vomiting, swelling of the belly or failure to pass stool.
  • Follow-up care:  Follow up with the pediatrician at regular scheduled appointments after discharge to be sure the infant is eating normally, stooling and gaining weight.

Long-Term Outcomes (“Are there future conditions to worry about?”)

  • The long term outcome for meconium plug syndrome is excellent. Infants have normal eating, stooling and growth. No further evaluation or treatment is needed.
  • If the patient is found to have Hirschsprung disease or cystic fibrosis, overall outcomes are different.

Updated: 11/2016
Author: Joanne E. Baerg, MD
Editors: Patricia Lange, MD; Marjorie J. Arca, MD