CASE 5280 Published on 27.03.2008

Meconium ileus

Section

Paediatric radiology

Case Type

Clinical Cases

Authors

Rodríguez Fernández, Paula; Vázquez Castelo, José Luis.

Patient

2 days, male

Clinical History
2-day-old baby boy. 33 weeks gestational age. First son. No abnormalities on prenatal US
Imaging Findings
A 2-day-old baby boy with failure to pass meconium and progressive abdominal distension. The nasogastric tube had bilious contents. Progressively the patient deteriorates and was intubated. Plain film of the abdomen was obtained showing multiple dilated bowel loops, in keeping with low intestinal obstruction. We then performed a contrast enema with two purposes: diagnostic and therapeutic. First, we used Optiray 160 (slightly hyperosmolar, 355 mOsm/l). It showed a microcolon. The rectum was normal. The contrast reached the terminal ileum that was packed with meconium. Diagnosis: Meconium Ileus. Once the diagnosis was known, we tried to be therapeutic: we changed the contrast to half-strength gastrografin (which is more hyperosmolar) and repeated the enema. The idea being to go as further back as possible and trying to hydrate the thick meconium to make it more fluid. In the following days, more enemas were needed. The patient did well and is currently fine.
Discussion
The fundamental differential diagnosis of newborns with low intestinal obstruction consists of four conditions. Two involve the colon (Hirschsprung´s disease and small left colon syndrome). The other two affect the distal ileum (ileal atresia and meconium ileus). In our patient, the rectum was larger than the sigmoid therefore “excluding” Hirschsprung disease. The entire colon was small not only the descending colon, therefore we ruled out small left colon syndrome. When contrast refluxed into the distal ileum, it was not atretic instead it was dilated and filled with meconium. Meconium ileus is most often seen in the first few days of life in neonates with cystic fibrosis (Meconium ileus occurs in 15 % of patients with cystic fibrosis) and can rarely occur in infants with a normal pancreas. It accounts for about 20-30 % of cases of intestinal obstruction in newborns and it is due to thick meconium impacted in the terminal ileum. Typically, patients will present with progressive abdominal distension and bilious vomiting. The dilated bowel loops are often palpable and visible through the abdominal wall. Abdominal plain film reveals multiple dilated bowel loops. Contrast enema shows a microcolon and an ileum packed with meconium. Uncomplicated meconium ileus may be successfully treated with dilute gastrografin enema. If hydrostatic therapy fails, surgery is required to relieve the obstruction.
Differential Diagnosis List
Meconium ileus
Final Diagnosis
Meconium ileus
Case information
URL: https://www.eurorad.org/case/5280
DOI: 10.1594/EURORAD/CASE.5280
ISSN: 1563-4086