DESCRIPTION

Reduction in bowel absorptive capacity after intestinal resection, causing inability to meet fluid and/or nutrient requirements

EPIDEMIOLOGY

• 80% of cases develop within the newborn period. Necrotizing enterocolitis accounts for ~30% of overall cases of short bowel syndrome.
• Incidence is approximately 24.5 in 100,000 live births per year.

ETIOLOGY

• Infants: necrotizing enterocolitis, intestinal atresia, gastroschisis, long segment Hirschsprung disease, malrotation with volvulus, cystic fibrosis–associated meconium ileus
• Older children: intestinal resection associated with Crohn disease, trauma, mesenteric ischemia, radiation enteritis

RISK FACTORS

• Preterm infants with necrotizing enterocolitis are at highest risk.
• Other perinatal and congenital intestinal diseases, including intestinal atresia, gastroschisis, long segment Hirschsprung disease, and malrotation with volvulus, also increase the risk of significant bowel resection, leading to short bowel syndrome.

GENERAL PREVENTION

Early diagnosis and surgical consultation of intestinal pathology may decrease the extent of damage leading to nonviable intestines that require resection.

PATHOPHYSIOLOGY

• Marked decrease in intestinal bowel length from resection decreases surface area for absorption; normal small bowel length for a full-term infant is 200 to 300 cm and 150 to 200 cm at 26 weeks’ gestation
• Supplementation of fluid, electrolytes, vitamins, and trace elements via parenteral nutrition, enteral formulas, infusions (iron), or injections (B₁₂) may be necessary. Extent and type of requirements are based on location and length of bowel resected.
• Hypersecretion: Transient gastric acid hypersecretion increases fluid volume that is entering the small bowel and impairs function of intestinal digestive enzymes, leading to increased stool or ostomy output.
• Adaptation: Structural adaptation by increasing absorptive capacity of remaining bowel; functional adaptation by slowing intestinal transit; small bowel dilation results in small bowel bacterial overgrowth (SBBO).

COMMONLY ASSOCIATED CONDITIONS

Intestinal failure: This condition encompasses short bowel syndrome, as well as other pathologies with intact bowel, but there is an inability to meet fluid and/or nutrient requirements.