SBS occurs due to the physical loss or the loss of function of a portion of the small and/or large intestine. Consequently, individuals with SBS often have a reduced ability to absorb nutrients.

SBS is most commonly associated with the surgical removal of half or more of the small intestine. Such surgery is performed to treat intestinal diseases such as Crohn's disease, injury or trauma to the small bowel, or congenital birth defects.

In people with SBS, diarrhea is common, often severe and can cause dehydration, which can even be life threatening. It can also lead to malnutrition, unintended weight loss, and additional symptoms due to the loss of essential vitamins and minerals. In some cases, SBS can lead to severe, disabling, and life-threatening complications.