Short bowel syndrome

Short bowel syndrome (SBS, also short gut syndrome or simply short gut) is a malabsorption disorder caused by the surgical removal of the small intestine, or rarely due to the complete dysfunction of a large segment of bowel. Most cases are acquired, although some children are born with a congenital short bowel.

Signs and symptoms

The symptoms of short bowel syndrome can include:

Patients with short bowel syndrome may have complications caused by malabsorption of vitamins and minerals, such as deficiencies in vitamins A, D, E, K, B9 (folic acid), and B12, calcium, magnesium, iron, and zinc. These may appear as anemia, hyperkeratosis (scaling of the skin), easy bruising, muscle spasms, poor blood clotting, and bone pain.

Causes

Short bowel syndrome in adults and children is usually caused by surgery for:

  • Crohn’s disease, an inflammatory disorder of the digestive tract
  • Volvulus, a spontaneous twisting of the small intestine that cuts off the blood supply and leads to tissue death
  • Tumors of the small intestine
  • Injury or trauma to the small intestine
  • Necrotizing enterocolitis (premature newborn)
  • Bypass surgery to treat obesity
  • Surgery to remove diseases or damaged portion of the small intestine

Pathophysiology

In healthy adults, the small intestine has an average length of approximately 6 meters (19.7 feet). Short bowel syndrome usually develops when there is less than 2 meters (6.6 feet) of the small intestine left to absorb sufficient nutrients.

Short bowel syndrome caused by the surgical removal of a portion of the bowel may be a temporary condition, due to the adaptive property of the small intestine.

In a process called intestinal adaptation, physiological changes to the remaining portion of the small intestine occur to increase its absorptive capacity. These changes include:

  • Enlargement and lengthening of the villi found in the lining
  • Increase in the diameter of the small intestine
  • Slow down in peristalsis or movement of food through the small intestine

Treatments

Symptoms of short bowel syndrome are usually addressed with medication. These include:

Prognosis

There is no cure for short bowel syndrome except transplant. In newborn infants, the 4-year survival rate on parenteral nutrition is approximately 70%. In newborn infants with less than 10% of expected intestinal length, 5 year survival is approximately 20%. Some studies suggest that much of the mortality is due to a complication of the total parenteral nutrition (TPN), especially chronic liver disease. Much hope is vested in Omegaven, a type of lipid TPN feed, in which recent case reports suggest the risk of liver disease is much lower.