Digestive

Meconium Ileus

Content reviewed against published NIH, AAP, Mayo Clinic guidelines

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Digestive issues are common in infants and toddlers. If your baby is experiencing meconium ileus, here is what you need to know.

The short answer

Meconium ileus is a type of neonatal bowel obstruction caused by abnormally thick, sticky meconium that blocks the ileum (last part of the small intestine). It is the earliest manifestation of cystic fibrosis (CF), occurring in about 15-20% of newborns with CF. It requires immediate medical evaluation and treatment, which may be non-surgical (contrast enema) or surgical depending on severity and complications.

Key takeaways

  • Meconium ileus is a type of neonatal bowel obstruction caused by abnormally thick, sticky meconium that blocks the ileum (last part of the small intestine). It is the earliest manifestation of cystic fibrosis (CF), occurring in about 15-20% of newborns with CF. It requires immediate medical evaluation and treatment, which may be non-surgical (contrast enema) or surgical depending on severity and complications.
  • Usually normal when: The meconium ileus was treated successfully and the baby is now passing stool and feeding well
  • Call your doctor if: Your newborn has a distended abdomen, is not passing stool, and is vomiting (especially green/bilious vomit), as these are signs of bowel obstruction requiring emergency evaluation
  • Varies by age — see the age-by-age breakdown below
“The biggest concern with vomiting is dehydration. Young children can become dehydrated quickly, so it's important to replace fluids. Offer small amounts of an oral rehydration solution frequently.”
— Vomiting in Children, American Academy of Pediatrics (AAP)

This is one of the most common questions parents ask. Searching for answers means you care.

By Age

What to expect by age

0-24 hours

Meconium ileus typically presents within the first day of life with signs of intestinal obstruction: abdominal distension, failure to pass meconium, and bilious (green) vomiting. The abdomen may appear visibly swollen and feel doughy. Sometimes, thickened loops of intestine can be felt or seen through the thin abdominal wall. Prenatal ultrasound may have shown dilated bowel or a hyperechoic (bright) mass, raising suspicion before birth. An abdominal X-ray will show dilated loops of bowel and may show a characteristic "soap bubble" or "ground glass" appearance in the right lower abdomen.

1-3 days

Diagnosis is typically confirmed through imaging studies. A contrast enema using water-soluble contrast (Gastrografin) can be both diagnostic and therapeutic, as the hyperosmolar contrast can help loosen and evacuate the thick meconium plug. This succeeds in approximately 50% of uncomplicated cases. If the contrast enema does not relieve the obstruction, or if there are complications such as volvulus (twisting of the bowel), atresia (absence of part of the bowel), or perforation, surgery is required. The surgical team will also test for cystic fibrosis, as it is the underlying cause in the majority of cases.

3-14 days

After successful treatment (either by contrast enema or surgery), the baby will remain in the hospital for recovery. Feeding is gradually introduced once bowel function resumes (indicated by passing stool and tolerating feeds without vomiting). Genetic testing for cystic fibrosis (sweat chloride test and/or genetic analysis) will be performed. If CF is confirmed, the baby will be started on pancreatic enzyme replacement therapy to aid digestion and connected with a CF care team. Recovery from uncomplicated cases is generally good.

2 weeks - 3 months

If cystic fibrosis has been confirmed, ongoing management includes pancreatic enzyme replacement with feeds, monitoring of growth and nutrition, and connection with a specialized CF center. Babies who had surgical treatment will need follow-up to ensure the bowel is functioning normally and there are no complications such as adhesions or strictures. Even if the immediate obstruction is resolved, close developmental and nutritional monitoring is important. With modern CF treatment, outcomes have improved significantly.

What Should You Do?

When to take action

Probably normal when...
  • The meconium ileus was treated successfully and the baby is now passing stool and feeding well
  • Genetic testing has been completed and results have been reviewed with your medical team
  • The baby is growing well on pancreatic enzyme replacement therapy (if CF was confirmed)
  • Follow-up imaging or examinations show the bowel is functioning normally after treatment
Mention at your next visit when...
  • Your baby had meconium ileus and you notice any changes in stool patterns, feeding, or growth
  • You have questions about cystic fibrosis diagnosis, management, or genetic counseling
  • Your baby seems to have difficulty with feeds or is not gaining weight as expected after treatment
Act now when...
  • Your newborn has a distended abdomen, is not passing stool, and is vomiting (especially green/bilious vomit), as these are signs of bowel obstruction requiring emergency evaluation
  • Your baby who previously had meconium ileus develops new vomiting, abdominal distension, or stops passing stool, as this could indicate a new obstruction or complication

Doctor Visit Checklist

Bring this checklist to your next pediatrician visit to discuss Meconium Ileus.

Things to mention

  • Your baby had meconium ileus and you notice any changes in stool patterns, feeding, or growth
  • You have questions about cystic fibrosis diagnosis, management, or genetic counseling
  • Your baby seems to have difficulty with feeds or is not gaining weight as expected after treatment

Observations to share

  • Your baby had meconium ileus and you notice any changes in stool patterns, feeding, or growth
  • You have questions about cystic fibrosis diagnosis, management, or genetic counseling
  • Your baby seems to have difficulty with feeds or is not gaining weight as expected after treatment

Urgent signs to report immediately

  • Your newborn has a distended abdomen, is not passing stool, and is vomiting (especially green/bilious vomit), as these are signs of bowel obstruction requiring emergency evaluation
  • Your baby who previously had meconium ileus develops new vomiting, abdominal distension, or stops passing stool, as this could indicate a new obstruction or complication

My notes

From ismybabyalright.com — free, evidence-based baby health guides

Triage

Vomiting Decision Tree

Evaluate vomiting severity and decide when to call the doctor.

Guide

Poop Color & Texture Guide

What your baby's poop color and consistency mean, and when to worry.

Milestone

Month-by-Month Development

Detailed monthly development guides from birth through 24 months.

Guide

When to Call the Doctor

General guide on when to call the pediatrician, visit urgent care, or go to the ER.

Frequently asked questions

Is meconium ileus normal?
Meconium ileus is a type of neonatal bowel obstruction caused by abnormally thick, sticky meconium that blocks the ileum (last part of the small intestine). It is the earliest manifestation of cystic fibrosis (CF), occurring in about 15-20% of newborns with CF. It requires immediate medical evaluation and treatment, which may be non-surgical (contrast enema) or surgical depending on severity and complications.
When should I call the doctor about meconium ileus?
Your newborn has a distended abdomen, is not passing stool, and is vomiting (especially green/bilious vomit), as these are signs of bowel obstruction requiring emergency evaluation Your baby who previously had meconium ileus develops new vomiting, abdominal distension, or stops passing stool, as this could indicate a new obstruction or complication
When is meconium ileus normal?
The meconium ileus was treated successfully and the baby is now passing stool and feeding well Genetic testing has been completed and results have been reviewed with your medical team The baby is growing well on pancreatic enzyme replacement therapy (if CF was confirmed)
What causes meconium ileus?
Meconium ileus is a type of neonatal bowel obstruction caused by abnormally thick, sticky meconium that blocks the ileum (last part of the small intestine). It is the earliest manifestation of cystic fibrosis (CF), occurring in about 15-20% of newborns with CF. It requires immediate medical evaluation and treatment, which may be non-surgical (contrast enema) or surgical depending on severity and complications. Common explanations include: The meconium ileus was treated successfully and the baby is now passing stool and feeding well. Genetic testing has been completed and results have been reviewed with your medical team.
What should I mention to my pediatrician about meconium ileus?
You should mention meconium ileus at your next visit if: Your baby had meconium ileus and you notice any changes in stool patterns, feeding, or growth. You have questions about cystic fibrosis diagnosis, management, or genetic counseling. Your baby seems to have difficulty with feeds or is not gaining weight as expected after treatment.
Is meconium ileus normal at 0-24 hours?
Meconium ileus typically presents within the first day of life with signs of intestinal obstruction: abdominal distension, failure to pass meconium, and bilious (green) vomiting. The abdomen may appear visibly swollen and feel doughy. Sometimes, thickened loops of intestine can be felt or seen through the thin abdominal wall. Prenatal ultrasound may have shown dilated bowel or a hyperechoic (bright) mass, raising suspicion before birth. An abdominal X-ray will show dilated loops of bowel and may show a characteristic "soap bubble" or "ground glass" appearance in the right lower abdomen.
Is meconium ileus normal at 1-3 days?
Diagnosis is typically confirmed through imaging studies. A contrast enema using water-soluble contrast (Gastrografin) can be both diagnostic and therapeutic, as the hyperosmolar contrast can help loosen and evacuate the thick meconium plug. This succeeds in approximately 50% of uncomplicated cases. If the contrast enema does not relieve the obstruction, or if there are complications such as volvulus (twisting of the bowel), atresia (absence of part of the bowel), or perforation, surgery is required. The surgical team will also test for cystic fibrosis, as it is the underlying cause in the majority of cases.
Should I go to the ER for meconium ileus?
Seek emergency care if your newborn has a distended abdomen, is not passing stool, and is vomiting (especially green/bilious vomit), as these are signs of bowel obstruction requiring emergency evaluation, or if your baby who previously had meconium ileus develops new vomiting, abdominal distension, or stops passing stool, as this could indicate a new obstruction or complication. When in doubt, call your pediatrician's after-hours line for guidance.
Does meconium ileus go away on its own?
In many cases, meconium ileus resolves on its own, especially when the meconium ileus was treated successfully and the baby is now passing stool and feeding well. By 2 weeks - 3 months, if cystic fibrosis has been confirmed, ongoing management includes pancreatic enzyme replacement with feeds, monitoring of growth and nutrition, and connection with a specialized CF center. Babies who had surgical treatment will need follow-up to ensure the bowel is functioning normally and there are no complications such as adhesions or strictures. Even if the immediate obstruction is resolved, close developmental and nutritional monitoring is important. With modern CF treatment, outcomes have improved significantly.
NIHAAPMAYO CLINIC

References

  1. [1]MedlinePlus. Meconium Ileus. National Library of Medicine. NIH
  2. [2]American Academy of Pediatrics. Cystic Fibrosis Clinical Care Guidelines. Pediatrics. AAP
  3. [3]Mayo Clinic. Cystic Fibrosis. Mayo Foundation for Medical Education and Research. Mayo Clinic

All content follows our editorial policy and is reviewed against published clinical guidelines.

2,705 evidence-based guides6 authoritative medical sources

Related Resources

Poop Color GuideVomiting TriageBaby Tracker

Bottom line

Most cases of meconium ileus are normal. Talk to your pediatrician if your newborn has a distended abdomen, is not passing stool, and is vomiting (especially green/bilious vomit), as these are signs of bowel obstruction requiring emergency evaluation.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.

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