Meconium Ileus

Overview

Meconium is the thick, dark first stool that a baby normally passes within the first day or two after birth. In meconium ileus, this stool is abnormally thick and sticky, so it plugs the lower small intestine and blocks the bowel. It is one of the earliest causes of intestinal obstruction in newborns.

Meconium ileus is strongly associated with cystic fibrosis, an inherited condition that makes body secretions thick. In fact, meconium ileus is often the very first sign that a baby has cystic fibrosis. The blockage is a medical emergency in the newborn period and needs prompt treatment, but with timely care most babies do well. Because of the close connection with cystic fibrosis, the diagnosis of meconium ileus usually prompts testing that can confirm cystic fibrosis early and allow specialized care to begin right away.

Symptoms

Symptoms appear in the first day or two of life:

• Failure to pass the first stool (meconium) within about 24 to 48 hours
• A swollen, distended belly
• Vomiting, often green or yellow (bile-stained)
• Feeding poorly or refusing to feed
• Visible loops of bowel through the abdominal wall in some cases

A newborn with a swollen belly, green vomiting, and no stool needs urgent medical evaluation, as these signal a bowel blockage.

Causes

Meconium ileus happens when the meconium is too thick and sticky to move through the intestine normally.

• Cystic fibrosis: The great majority of babies with meconium ileus have cystic fibrosis. In this condition, the pancreas and intestinal glands produce abnormally thick secretions, making the meconium dense and pasty.
• Thickened secretions: The sticky meconium adheres to the bowel wall and forms a plug, usually in the last part of the small intestine (the ileum).

Because of the strong link, every baby with meconium ileus is evaluated for cystic fibrosis.

Risk Factors

• A family history of cystic fibrosis
• Both parents being carriers of a cystic fibrosis gene change
• Certain ethnic backgrounds in which cystic fibrosis is more common
• Other features of cystic fibrosis identified on newborn screening

Diagnosis

Diagnosis is made in the newborn period and includes testing for cystic fibrosis:

• Physical examination: Assessing belly swelling, vomiting, and stool.
• X-rays: Abdominal X-rays often show dilated bowel loops and a bubbly appearance from gas mixed with thick meconium.
• Contrast enema: A dye study of the bowel can both confirm the diagnosis and, in some cases, help clear the blockage.
• Cystic fibrosis testing: Sweat testing and genetic testing are done because of the strong association.

Treatment

Treatment first aims to clear the blockage and stabilize the baby.

• Stabilization: A stomach tube to relieve pressure and intravenous fluids to correct dehydration.
• Contrast enema: A special enema can sometimes break up and flush out the meconium plug without surgery.
• Surgery: If the enema does not work, or if there is a complication such as a twist, tear, or dead segment of bowel, surgery is needed to remove the blockage and repair the intestine.
• Cystic fibrosis care: Babies confirmed to have cystic fibrosis begin lifelong management, including enzyme support for digestion and care for the lungs.

With prompt treatment, most babies recover, though those with cystic fibrosis need ongoing specialized care throughout childhood and beyond. Early diagnosis and a coordinated team approach give these babies the best possible start.

Prevention

Meconium ileus itself cannot be prevented, but planning and early detection help:

• Genetic carrier testing before or during pregnancy can identify couples at risk of having a child with cystic fibrosis
• Newborn screening helps detect cystic fibrosis early
• Delivering at a hospital with newborn surgical care if a blockage is suspected before birth

When to See a Doctor

Meconium ileus is usually identified by the hospital team soon after birth. Seek emergency care right away if a newborn does not pass stool in the first day or two, has a swollen belly, vomits green or yellow fluid, or appears unwell.

If your baby is diagnosed with meconium ileus, follow up promptly with cystic fibrosis testing and specialist care, since early diagnosis improves long-term health.

Related Topics

Frequently Asked Questions

References

1. Cystic Fibrosis Foundation. About Cystic Fibrosis.
2. MedlinePlus, U.S. National Library of Medicine. Meconium ileus.
3. Mayo Clinic. Cystic fibrosis.
4. American Pediatric Surgical Association. Meconium ileus.