Meconium Ileus

Overview

What is meconium ileus?

Meconium ileus is a blockage in your newborn’s small intestine. Excessively thick meconium causes this blockage. Meconium is your baby’s first poop. It’s darker, thicker and stickier than normal poop. Meconium forms when your baby swallows amniotic fluid.

Amniotic fluid is the fluid that surrounds and cushions your baby inside of your womb during fetal development. As amniotic fluid passes through your baby's intestines, they absorb the water part of the amniotic fluid. A sticky, tar-like substance is left behind. Your newborn normally passes their first poop 24 to 48 hours within birth.

If your baby’s meconium is abnormally thick or tar-like, it can block the last part of their small intestine. This part is called the ileum. Above the blocked ileum, your newborn’s small intestine will enlarge. This causes abdominal swelling. Below the ileum, your newborn’s large intestine will narrow because nothing is passing through it. Think of a clogged toilet: If you use too much toilet paper, it won’t flush. The toilet will fill up with water and waste, while nothing will pass through the pipes.

What are the different types of meconium ileus?

Meconium ileus can be simple or complex. Simple meconium ileus means your baby’s meconium obstructs their ileum and small intestine. But they don’t have any further complications.

Complex meconium ileus means your baby’s meconium builds up to the point of causing intense pressure and swelling on their intestine. This can lead to severe complications. These complications may include:

  • Malrotation: Malrotation means your baby’s intestine doesn’t form properly. This can happen due to prenatal volvulus. Prenatal volvulus means your baby’s intestine twists around itself. This is a dangerous condition because it can block the intestine’s blood supply.
  • Intestinal atresia: If twisting blocks off your baby’s blood supply to their intestine, it can cause intestinal atresia. Intestinal atresia means areas of your baby’s small intestine won’t form completely.
  • Perforation: Perforation means a hole develops in your baby’s intestine. Perforation is dangerous because meconium can leak into your baby’s abdominal cavity. If perforation occurs after birth, meconium leakage can cause infection. This can lead to shock and death.

Who does meconium ileus affect?

Meconium ileus usually happens as a result of cystic fibrosis. Meconium ileus is the first sign of cystic fibrosis in 10% to 20% of children with the disease. Studies have also shown that up to 90% of infants with meconium ileus have cystic fibrosis.

Symptoms and Causes

What causes meconium ileus?

Meconium ileus is frequently an early sign of cystic fibrosis. Cystic fibrosis is a genetic condition that causes your child’s intestinal secretions to be abnormally thick and sticky. These secretions stick to the lining of your child’s intestine, causing obstructions. If your child has meconium ileus, they may develop other symptoms of cystic fibrosis later in life.

What are the symptoms of meconium ileus?

If your newborn hasn’t passed their first poop within 24 to 48 hours, it’s a sign of meconium ileus. Other symptoms include vomiting and abdominal swelling. The swelling may cause difficulty breathing.

Your child’s healthcare provider may be able to feel large loops of small intestine through their abdominal wall. If you baby has a perforated intestine, they may also develop:

  • Redness.
  • Tenderness.
  • Fever.
  • Shock.

Diagnosis and Tests

How is meconium ileus diagnosed?

Diagnosis of meconium ileus can sometimes take place before birth. Your healthcare provider may see signs of a blockage on a prenatal ultrasound.

More often, your baby’s healthcare provider will diagnose meconium ileus after birth. They may diagnose the condition based on your newborn’s symptoms. They’ll consider meconium ileus if:

  • Cystic fibrosis runs in your family.
  • Your newborn tests positive for cystic fibrosis on their newborn screening tests.

What tests will be done to diagnose meconium ileus?

If your baby’s healthcare provider suspects meconium ileus, they’ll order an abdominal X-ray. X-rays can show enlarged loops of small intestine. When meconium mixes with swallowed air, radiologists may see what looks like soap bubbles in your baby’s small intestine. If there’s a complete obstruction, no air will be present in your baby’s rectum.

The radiology department may also perform a contrast enema. Contrast is a liquid that’s visible on X-rays. The enema may show their large intestine is narrower than normal. It can also identify malrotation. If the enema shows malrotation, your baby’s healthcare provider will order an upper gastrointestinal series (UGI). A UGI can confirm a malrotation diagnosis. It can also help evaluate where their intestine is twisting.

Your infant’s healthcare provider may also order a sweat test to confirm or rule out cystic fibrosis.

Management and Treatment

How is meconium ileus treated?

If your newborn has complex meconium ileus (such as a twisted or perforated intestine), they’ll need surgery immediately.

If your baby has simple meconium ileus, their healthcare provider may first try to wash out the blockage using an enema. The enema may contain a special drug that breaks down and softens thickened meconium. The enema solution may help the meconium pass through your baby’s intestine and out of their rectum.

Your baby’s healthcare provider will slowly infuse the solution through a catheter inserted in your baby’s rectum. They’ll use a medical imaging procedure called fluoroscopy. Fluoroscopy passes X-rays through your baby’s body to create a real-time video of the tissues inside of your baby’s body.

If an enema doesn’t work, your baby’s healthcare provider will need to perform surgery. They’ll cut open your baby’s intestine and remove the meconium. Depending on your baby’s condition, they may bring the open ends of your baby’s intestine out through the wall of their abdomen (ileostomy). They’ll do more enemas through the open ends of their intestine until they remove all of the meconium. Your child’s healthcare provider will perform another operation to put the ends of their intestine back together.

Prevention

How can I prevent meconium ileus in my baby?

You can’t prevent meconium ileus. Cystic fibrosis usually causes the condition, which is an inherited disease. If you’re pregnant or planning on pregnancy, you may want to consider prenatal cystic fibrosis carrier screening. Screening can help you understand your risk of having a child with the condition.

Outlook / Prognosis

What is the outlook if my baby has meconium ileus?

The prognosis for even complicated cases of meconium ileus is usually good. Meconium ileus is often a sign of cystic fibrosis. But with early diagnosis and treatment, the long-term outlook for your baby’s lung function, nutrition intake and risk of infection is good. If meconium ileus is left untreated, your baby’s prognosis is poor. It’s vital to seek treatment right away if your baby has meconium ileus.

A note from Cleveland Clinic

You may be scared and confused if your baby has meconium ileus. As with many health conditions, early diagnosis and treatment usually result in a successful outcome. While meconium ileus is typically a sign of cystic fibrosis, it’s important to remember the disease has treatment options. Talk with your baby’s healthcare provider about any concerns you have. They’ll work with you to make sure your baby has the best outcome possible.

Last reviewed by a Cleveland Clinic medical professional on 03/03/2022.

References

  • Merck Manual. Meconium Ileus. (https://www.merckmanuals.com/home/children-s-health-issues/gastrointestinal-gi-and-liver-problems-in-newborns/meconium-ileus) Accessed 3/3/2022.
  • Parikh NS, Ibrahim S, Ahlawat R. Meconium Ileus. (https://www.ncbi.nlm.nih.gov/books/NBK537008/) [Updated 2021 Aug 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. Accessed 3/3/2022.
  • Sathe M, Houwen R. Meconium ileus in Cystic Fibrosis. (https://pubmed.ncbi.nlm.nih.gov/28986020/) J Cyst Fibros. 2017;16 Suppl 2:S32-S39. Accessed 3/3/2022.
  • Waldhausen JHT, Richards M. Meconium Ileus. (https://pubmed.ncbi.nlm.nih.gov/29487495/) Clin Colon Rectal Surg. 2018;31(2):121-126. Accessed 3/3/2022.

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