• Pyloric stenosis, 25%
• Intussusception, 18%
• Atresia of the intestine, 15%
• Imperforate anus, 11%
• Hirschsprung disease, 6%
• Postoperative adhesions, 5%
• Meconium ileus, plug, 5%
• Malrotation, 5%
• Annular pancreas, 3%
• Meckel diverticulum, 3%

• Intraluminal: polyp, mass, bezoar, foreign body, parasites, and tumor
• Intramural: stricture, tumor, hematoma
• Extrinsic: postoperative adhesions, adhesions from peritonitis, hernia, volvulus, and tumor

• No genetic predisposition to intestinal obstruction in general cases

• The different causes of intestinal obstruction have their own identified epidemiologic patterns: small bowel obstruction secondary to Ascaris lumbricoides in Calcutta, India; colonic volvulus secondary to aerophagia and constipation in mentally retarded children; or meconium ileus equivalent in children with cystic fibrosis.
• Down syndrome with a higher prevalence of duodenal atresia

• Excellent in cases of simple intestinal obstruction without strangulation

• Metabolic: meconium ileus, electrolyte disturbance
• Congenital: esophageal atresia, intestinal atresia, duplication of bowel, malrotation, diaphragmatic hernia, Hirschsprung disease, imperforate anus, annular pancreas, pyloric stenosis
• Miscellaneous: adhesive bands, intussusception, meconium plug, volvulus, postoperative adhesions

• Pain is one of the cardinal manifestations of intestinal obstruction, resulting from distention of the intestine, producing visceral pain that is poorly localized, with nausea and vomiting.
• Pain that is well localized and associated with tenderness and rigidity results from peritonitis.
• A history of bilious emesis and feculent characteristics confirm obstruction.
• Passage of bloody stool and mucus may suggest strangulation.
• Elicit any family history of cystic fibrosis, polyps, and previous abdominal surgery, as well as recent weight loss or spinal surgery.

• Palpation may reveal the presence of hernia, a mass suggestive of feces or intussusception, and tenderness or rigidity.
• Presence of scoliosis or kyphosis should be recognized.
• Rectal examination will reveal, at times, a palpable polyp or intussusceptum.

• Electrolyte balance, including sodium, chloride, bicarbonate, and potassium, are necessary for assessment of hydration and third spacing of fluids.
• No particular laboratory test will confirm the diagnosis, other than imaging techniques, as described below.

• Plain abdominal radiographs in the supine and erect views will identify the classical features of a gasless abdomen, with air-fluid levels and distended loops of intestine.
• Paralytic ileus may present with dilation of the small and large intestines.
• Ultrasonography has been used to identify a mass (i.e., perforated appendix) as the cause of the obstruction.
• In isolated cases, contrast examinations may be helpful in making a diagnosis (e.g., barium enema to confirm intussusception or Hirschsprung disease, and upper GI series to exclude malrotation or volvulus).

• Initial stages:
  • Hold oral intake.
  • Decompress the stomach with a nasogastric tube.
  • Hydration IV and correct electrolyte imbalance
  • Identify etiology of obstruction and establish definitive repair.
• Surgical:
  • In cases of strangulation, immediate surgical options may be needed in cases of perforation and peritonitis. In isolated cases of distal obstruction secondary to intussusception, surgery is avoided with the institution of hydrostatic or air reduction of the mass effect.

Q: Will my child need surgery for this problem?
A: Most likely; surgical treatment is necessary to correct the cause of intestinal obstruction except in a few cases, such as intussusception, pseudo-obstruction, and paralytic ileus.

Q: What is the most common cause of this problem in my 3-day-old son?
A: In an infant, the most common causes are atresias, which are absences of the normal amount of intestine in the abdomen. Other causes are defects in the large intestine, such as Hirschsprung disease.

Madonna MB, Boswell WC, Arensman RM. Acute abdomen. Semin Pediatr Surg 1997;6(2):105–111.

Villamizar E, Mendez M, Bonilla E, Varon H, de Onatra S. Ascaris lumbricoides infestation as a cause of intestinal obstruction in children: experience with 87 cases. J Pediatr Surg 1996;31(1):201–206.

Wesson D. Acute intestinal obstruction. In: Walker W, Durie P, Hamilton JR, et al., eds. Pediatric gastrointestinal disease. Philadelphia: BC Decker, 1994: 486–494.