Short bowel syndrome

Short bowel syndrome is a malabsorption disorder caused by either the surgical removal of the small intestine or the loss of its absorptive function due to diseases.

In healthy adults, the small intestine has an average length of approximately 6 meters (20 feet). Short bowel syndrome usually appears when there is less than 1.8 meters (6 feet) of the small intestine left to absorb sufficient nutrients.

Symptoms

The symptoms of short bowel syndrome include:

Abdominal pain
Diarrhoea
Steatorrhoea or particularly foul-odored faeces
Oily or sticky stool
Fluid retention
Weight loss and malnutrition
Fatigue

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

Causes

Short bowel syndrome in adults is usually caused by:

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 necrosis or tissue death.
Cancer of the small intestine
Injury or trauma to the small intestine
Bowel bypass surgery to treat obesity, now a rarely performed surgical procedure to remove a portion of the small intestine.
Surgery to remove diseases or damaged portion of the small intestine.

This condition can also develop in premature infants who have necrotizing enterocolitis, a serious disease where dead tissues in the lining of the small intestine needs to be surgically removed.

Treatments

Symptoms of short bowel syndrome are usually addressed by prescription medicine. These include:

Anti-diarrheal medicine
Vitamin and mineral supplements
H2 blocker and proton pump inhibitors to reduce stomach acid
Lactase supplement
Surgery, including intestinal lengthening, tapering, and organ transplant.
Parenteral nutrition (or nutrition administered via intravenous line).

Intestinal adaptation

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

Prognosis

There is no cure for short bowel syndrome. In newborn infants, the 4-year survival rate on parenteral nutrition is approximately 70%.

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.

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