Radiography
Supine frontal view of the abdomen in a newborn with meconium plug syndrome demonstrates multiple dilated loops of bowel but no rectal gas.
A frontal view from contrast enema in a patient initially given a diagnosis of small left colon syndrome. A long filling defect is seen in the rectosigmoid with gradual transition to a more dilated proximal bowel. The infant failed to improve, and rectal biopsy confirmed Hirschsprung disease.
A lateral view from contrast enema in a newborn demonstrates a normal-to-decreased caliber "empty" distal colon and dilated proximal bowel containing multiple plugs. The child responded clinically and radiographically to a single enema.
Findings
Plain films usually demonstrate multiple dilated loops of bowel with absence of rectal gas. The presence or absence of air-fluid levels in the bowel is not helpful. Findings are similar to those of structural colonic or distal small bowel obstruction and help to exclude malrotation with volvulus or obstructing Ladd bands, in which the blockage usually occurs at the duodenum.
Contrast enema usually shows a moderately dilated colon filled with radiolucent material (the meconium plug). In the small left colon variant (see Image 3), a transition is seen from a relatively small to normal or increased caliber bowel in the region of the splenic flexure.
Degree of Confidence
Meconium plug syndrome is a diagnosis of exclusion. Contrast enema usually excludes congenital small bowel obstruction and rare colon abnormalities such as atresia or duplication. The main differential consideration is Hirschsprung disease, which is diagnosed eventually in approximately 10-30% of patients with apparent meconium plug syndrome (see Image 2).
Rare disorders that may partially simulate meconium plug syndrome include neuronal intestinal dysplasia, visceral neuropathies, and megacystis-microcolon-intestinal hypoperistalsis syndrome, also termed Berdon syndrome. However, radiographic and clinical features in these disorders usually are distinguished readily from meconium plug syndrome. A small (micro or mini) colon characterizes many of these diseases.
A more common problem is an infant with sepsis or metabolic disorder who presents with a nonobstructive ileus. In these patients, the intestinal dilatation resolves once the primary problem is treated.
The main problem in differential diagnosis, after the contrast enema has been performed, is Hirschsprung disease. The enema findings in neonatal Hirschsprung disease are not distinguishable from meconium plug syndrome. The most important point is the infant's response to supportive care and enemas.
Evaluate any infant with apparent meconium plug syndrome for Hirschsprung disease (rectal-suction biopsy) and other possible underlying disorders when findings persist after 1-2 enemas.
False Positives/Negatives
The normal infant's intestinal gas pattern often appears "gassy" by adult criteria. Typically, the width of a bowel loop does not exceed the width of one of the patient's lumbar vertebral bodies. Rectal gas often may be absent in the normal infant because the rectum is dependent and filled with meconium when the patient is supine. With the exception of the rectum, the colon and small bowel usually cannot be differentiated on plain film.
More on Meconium Plug Syndrome |
| Overview: Meconium Plug Syndrome |
 Imaging: Meconium Plug Syndrome |
| Follow-up: Meconium Plug Syndrome |
| Multimedia: Meconium Plug Syndrome |
| References |
| Further Reading |
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References
Keckler SJ, St Peter SD, Spilde TL, Tsao K, Ostlie DJ, Holcomb GW 3rd, et al. Current significance of meconium plug syndrome. J Pediatr Surg. May 2008;43(5):896-8. [Medline].
American Pediatric Surgical Association. Meconium Plug/Small Left Colon Syndrome. American Pediatric Surgical Association. Available at http://www.eapsa.org/parents/resources/plug.cfm. Accessed May 11, 2009.
Burge D, Drewett M. Meconium plug obstruction. Pediatr SurgInternational. 2004;20(2):108-10. [Medline].
American College of Radiology ACR Appropriateness Criteria. Vomiting in Infants up to 3 Months of Age. American College of Radiology. Available at http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonPediatricImaging/VomitinginInfantsupto3MonthsofAgeDoc11.aspx. Accessed May 12, 2009.
American College of Radiology. ACR Practic Guideline for the Performance of Pediatric Fluoroscopic Contrast Enema Examinations. American College of Radiology. Available at http://www.acr.org/SecondaryMainMenuCategories/quality_safety/guidelines/pediatric/pediatric_contrast_enema.aspx. Accessed May 12, 2009.
Krasna IH, Rosenfeld D, Salerno P. Is it necrotizing enterocolitis, microcolon of prematurity, or delayed meconium plug? A dilemma in the tiny premature infant. J Pediatr Surg. Jun 1996;31(6):855-8. [Medline].
McAlister WH, Kronemer KA. Emergency gastrointestinal radiology of the newborn. Radiol Clin North Am. Jul 1996;34(4):819-44. [Medline].
Olsen MM, Luck SR, Lloyd-Still J. The spectrum of meconium disease in infancy. J Pediatr Surg. Oct 1982;17(5):479-81. [Medline].
Sokal MM, Koenigsberger MR, Rose JS. Neonatal hypermagnesemia and the meconium-plug syndrome. N Engl J Med. Apr 13 1972;286(15):823-5. [Medline].
Steves M, Ricketts RR. Pneumoperitoneum in the newborn infant. Am Surg. Apr 1987;53(4):226-30. [Medline].
Swischuk LE. Meconium plug syndrome: a cause of neonatal intestinal obstruction. Am J Roentgenol Radium Ther Nucl Med. Jun 1968;103(2):339-46. [Medline].
Wood BP, Katzberg RW. Tween 80/diatrizoate enemas in bowel obstruction. AJR Am J Roentgenol. Apr 1978;130(4):747-50. [Medline].
Further Reading
Related eMedicine topics
Meconium Ileus
Bowel Obstruction in the Newborn
Small Left Colon Syndrome
Atresia, Stenosis, and Other Obstruction of the Colon
Keywords
meconium plug syndrome, functional immaturity of the colon, small left colon syndrome, Hirschsprung disease
