What is short bowel syndrome?

Short bowel syndrome is a condition in which the body cannot absorb enough fluids and nutrients because part of the small intestine is missing (usually due to prior surgery or illness), or is not working properly.

What does the small intestine do?

The small intestine is a part of the digestive system. The small intestine has three sections:

  • The duodenum, which is located next to the stomach (shortest section)
  • The jejunum, which lies between the duodenum and the ileum
  • The ileum, which is the longest section and connects to the large intestine (colon)

(The ileocecal valve forms a barrier between the ileum and the large intestine to prevent the contents of the large intestine from flowing back into the small intestine.)

The small intestine is where the absorption of fluids, proteins, carbohydrates (starches and sugars), iron, fats, vitamins, and minerals (such as calcium, sodium, and potassium) takes place. If the duodenum and a portion of the jejunum have been removed by surgery, the ileum can take on their role in absorbing nutrients. But if a substantial part of the jejunum or the ileum is removed, it is more difficult to obtain adequate nutrition. In these cases, nutrients usually have to be provided in a form other than food.

Children need more calories than adults because they are still growing. If a child is born with portions of the small intestine missing, it can lead to serious problems.

What causes short bowel syndrome?

Short bowel syndrome can occur as a congenital (present at birth) condition. For example, the small intestine might be abnormally short at birth, a section of the bowel might be missing, or the bowel does not form completely before birth (intestinal atresia).

In other cases, patients develop conditions in which a large section of the small intestine has to be removed by surgery. In newborns, especially premature infants, necrotizing enterocolitis (the inflammation and loss of blood flow to the intestine, leading to severe damage) is the most common cause of short bowel syndrome.

Other causes include:

  • Crohn's disease (the intestine becomes inflamed and scarred); in this condition SBS occurs primarily in patients who have undergone extensive surgery to the small bowel
  • Intussusception (part of the intestine is folded into another part and compromises the blood flow to the involved portion of the intestine)
  • Injury to the intestine due to:
    • Volvulus (twisting of the intestine)
    • Trauma (injury)
    • Gastroschisis (when the intestines develop outside the body prior to birth)
    • Narrowing or obstruction of the intestines
    • Tumors
    • Blood clots or abnormal blood flow (ischemia) affecting the circulation to the intestine

What are the symptoms of short bowel syndrome?

Symptoms of short bowel syndrome include:

  • Diarrhea. Watery diarrhea is the most common symptom of short bowel syndrome in infants and children.
  • Bloating
  • Excessive gas and/or foul-smelling stool
  • Poor appetite
  • Weight loss or inability to gain weight
  • Fatigue
  • Vomiting

Other complications can occur as a result of short bowel syndrome, including:

  • Dehydration
  • Vitamin, mineral, and/or electrolyte shortage or imbalance
  • Malnutrition
  • Severe diaper rash caused by frequent diarrhea
  • Abnormal eating habits
  • Kidney stones or gallstones caused by abnormal calcium or bile absorption
  • Bacterial overgrowth (high levels of bacteria in the intestine)

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