++
Gastrointestinal obstructions are categorized according to etiology
as either congenital or acquired.
These broad categories are not mutually exclusive. For example,
congenital lesions of the intestine such as an enteric duplication
or Meckel diverticulum may not cause obstruction until later in
life. Congenital anatomic defects and acquired disorders of the
intestine presenting in the first 30 days of life are characterized
as neonatal intestinal obstruction.
++
Clinical Features
and Differential Diagnosis
++
Neonatal Intestinal
Obstruction
++
The anatomic conditions that present with neonatal intestinal
obstruction and their diagnostic features are summarized in Table 389-1. Accurate diagnosis of neonatal
intestinal obstruction relies on a thorough history, careful examination,
and directed radiological studies.1 In a newborn
infant, postprandial nonbilious emesis, or spitting up, is quite
common and does not require urgent evaluation (see Chapter 394). In contrast, neonatal intestinal obstruction is usually
characterized by feeding intolerance, abdominal distention, bilious
emesis, and failure to pass meconium. Bilious emesis is most frequently
a consequence of mechanical intestinal obstruction, and prompt evaluation
is necessary to exclude life-threatening conditions such as necrotizing
enterocolitis or volvulus. The history provides clues to the potential
etiology of intestinal obstruction, but history and physical examination
alone are generally not reliable for establishment of a diagnosis.
For example, a 3-week-old infant with bilious emesis who has passed meconium
and previously tolerated feeding is unlikely to have intestinal
atresia as a cause of emesis and more likely to have intestinal
malrotation with midgut volvulus. Infants with trisomy 21 are more
likely to have congenital duodenal obstruction2 and
Hirschsprung disease. Neonates with anomalies of vertebral, anorectal,
cardiac, esophageal, renal, and limbs are more likely to have esophageal
atresia and anorectal malformations as
possible causes of intestinal obstruction (VACTERL association).
Extremely low birthweight, premature infants are much more likely
than term infants to develop necrotizing enterocolitis.
++