meconium plug syndrome
Meconium plug syndrome refers to a functional colonic obstruction in a newborn due to an obstructing meconium plug. It is usually transient and affects the left colon with meconium plugging the bowel distal to this segment. In this situation, it is also termed the small left colon syndrome.
Pathology
Associations
- may have a higher prevalence with maternal diabetes
- Hirschsprung disease in ~15%
- may be associated with cystic fibrosis
Radiographic features
Radiograph
May show multiple dilated bowel loops which are a non-specific finding. There may be a caliber change around the splenic flexure.
Fluoroscopy: contrast enema
Contrast enema may demonstrate a small caliber to the left colon with multiple filling defects within due to retained meconium. The rectum is usually normal in size, unlike Hirschsprung disease. The use of high osmolar ionic contrast media for enema in a neonate or infant is controversial due to the risks associated with fluid shift . The enema can be both diagnostic as well as therapeutic and is usually accompanied by the passage of meconium during or after the procedure.
Treatment and prognosis
Usually, resolves with time. Initial nonsurgical management includes rectal stimulation and contrast enema .
Differential diagnosis
On a plain radiograph consider most other causes of bowel obstruction. On a contrast enema consider:
- meconium ileus (right colon usually not dilated)
- long segment Hirschsprung disease (often has a reversed recto-sigmoid ratio)
- ileal atresia (on contrast enema)