Short bowel syndrome (SBS) is a malabsorptive state that is caused by either massive resection of the small intestine or by a congenital defect or disease-associated loss of absorption. It is a functional definition, implying a significant amount of malabsorption of both macronutrients and micronutrients, rather than a definition based upon on the loss of a specific length or segment of bowel.

The gastrointestinal tract responds to massive resection with a process called intestinal adaptation, wherein changes in intestinal morphology and function gradually increase absorptive capacity. Through this process, many patients eventually are able to transition off of parenteral nutrition (PN) to full enteral feeds and some even achieve full oral feeding. During the past two decades, advances in medical and surgical management have resulted in reduced mortality, shorter duration of PN, and better weight gain for infants with SBS compared with previous cohorts. Outcomes of SBS have also improved because of improvements in the prevention or management of the long-term complications, such as intestinal failure-associated liver disease (IFALD) and central venous catheter-associated bloodstream infections.