Short bowel syndrome

Synonyms

SBS

Overview

Short bowel syndrome is a group of problems related to poor absorption of nutrients that typically occurs in people who have had half or more of their small intestine removed. The small intestine and the large intestine, also called the colon, make up the bowel. The small intestine is where most digestion of food and absorption of nutrients occur. People with short bowel syndrome cannot absorb enough water, vitamins, and other nutrients from food to sustain life.

Symptoms

Main sing and symptoms:

  • Diarrhea 
  • Dehydration
  • Malnutrition
  • Weight loss. 

These problems can be severe and can cause death without proper treatment. Other symptoms may include:

  • Cramping
  • Bloating
  • Heartburn
  • Weakness and fatigue

Specific nutrient deficiencies may occur depending on what sections of the small intestine were removed or are not functioning properly.

Causes

The main cause of short bowel syndrome is surgical removal of half or more of the small intestine to treat intestinal diseases, injuries, or defects present at birth. In newborns, short bowel syndrome may occur following surgery to treat conditions such as:

  •  Necrotizing enterocolitis, a condition that occurs in premature infants and leads to the death of bowel tissue
  • Congenital defects of the bowel, such as midgut volvulus, omphalocele and gastroschisis, jejunoileal atresia, internal hernia, and congenital short bowel
  • Meconium ileus, a condition associated with cystic fibrosis.

 In children and adults, short bowel syndrome may occur following surgery to treat conditions such as:

  • Intussusception, a condition in which part of the intestine folds into another part of the intestine
  • Crohn’s disease, an inflammatory bowel disease
  • Bowel injury from loss of blood flow due to a blocked blood vessel
  • Bowel injury from trauma
  • Cancer and damage to the bowel caused by cancer treatment.

Short bowel syndrome can also be caused by disease or injury that prevents the small intestine from functioning as it should despite a normal length.

Prevention

After removal of a large portion of the small intestine, the remaining small intestine goes through a process of adaptation that increases its ability to absorb nutrients. The inner lining grows, increasing its absorptive surface area. Intestinal adaptation can take up to 2 years to occur. Researchers are studying intestinal adaptation and ways to help the remaining small intestine adapt more quickly and function better.

Diagnosis

If a person has had bowel surgery, or is known to have a bowel disorder that affects absorption, the appearance of symptoms such as diarrhoea and abdominal pain suggests short bowel syndrome. This condition is common after bowel resection and can improve in time, once intestinal adaptation takes place. Some of the tests to confirm the diagnosis of short bowel syndrome may include:

• Blood tests

• Stool examinations

Prognosis

There is no cure for short bowel syndrome. In newborn infants, the 4-year survival rate on parenteral nutrition is approximately 70%. Some studies suggest that much of the mortality is due to a complication of the TPN, especially chronic liver disease. Although promising, small intestine transplant has a mixed success rate, with postoperative mortality rate of up to 30%. One-year and 4-year survival rate are 90% and 60%, respectively.

Surgical procedures to lengthen dilated bowel include the Bianchi Procedure (where the bowel is cut in half and one end is sewn to the other) and a newer procedure called serial transverse enteroplasty (STEP—where the bowel is cut and stapled in a zigzag pattern). There is controversy over the efficacy of these procedures. They are usually performed by pediatric surgeons at quaternary hospital who specialize in small bowel surgery.

Treatment

The main treatment for short bowel syndrome is nutritional support. Treatment may involve use of oral rehydration solutions, parenteral nutrition, enteral nutrition, and medications. Oral rehydration solutions consist of sugar and salt liquids. Parenteral nutrition delivers fluids, electrolytes, and liquid nutrients into the bloodstream intravenously—through a tube placed in a vein. Enteral nutrition delivers liquid food to the stomach or small intestine through a feeding tube.

Specific treatment depends on the severity of the disease:

• Mild short bowel syndrome treatment involves eating small, frequent meals; taking fluid and nutritional supplements; and using medications to treat diarrhea.

• Moderate short bowel syndrome treatment is similar to that for mild disease with the addition of intravenous fluid and electrolyte supplements as needed.

• Severe short bowel syndrome treatment involves use of parenteral nutrition and oral rehydration solutions. Patients may receive enteral nutrition or continue normal eating even though most of the nutrients are not absorbed. Both enteral nutrition and normal eating stimulate the remaining intestine to function better and may allow patients to discontinue parenteral nutrition. Some people with severe short bowel syndrome require parenteral nutrition indefinitely.

 Long-term treatment and recovery depend in part on what sections of the small intestine were removed, how much remains, and how well the remaining small intestine adapts over time.

Intestinal transplantation may be an option for some patients for whom other treatments have failed and who have complications from long-term parenteral nutrition. These complications include blood infections, blood clots, and liver failure, which can lead to the need for liver transplantation.

Approved therapies:

  • Teduglutide [rDNA origin] (Gattex) - Treatment of adult patients with short bowel syndrome (SBS) who are dependent on parenteral support 
  • Glutamine (Nutrestore) - Treatment of short bowel syndrome in patients receiving specialized nutritional support when used in conjunction with a rercombinant human growth hormone that is approved for this indication. 
  • Somatropin (r-DNA) (Zorbitve) - Treatment of short bowel syndrome in patients receiving specialized nutritional support 

Resources

Refer to Research Publications.